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Alpha hydroxy acids | Antihistamines | Beta hydroxy acids | Botulinum toxin | Chemical peels | Compresses | Corticosteroids or steroids | Finasteride | Hair replacement surgery | Immunosuppressive drugs | Implants | Intralesional steroids | Lasers | Laser resurfacing | Minoxidil | Phototherapy | Retinoids | Sunscreens

Alpha-hydroxy acids became popular during the nineties because of their beneficial effects on wrinkles.

There are several varieties of AHAs:-

• Lactic acid derived from sour milk,
• Citric acid derived from citrus fruits,
• Tartaric acid from grapes,
• Glycolic acid from sugar cane,
• Pyruvic acid from papaya,
• Malic acid from apples,
• Mandelic acid from bitter almonds.

In other words, quite a few come from fruits, hence, its other name fruit acids. AHAs work by dissolving the cement that keeps our dead skin cells (the stratum corneum cells) together. In doing so, AHAs exfoliate the dead skin cells revealing the new cells underneath. This results in a smoother and more evenly toned skin. There are also studies to suggest that AHAs can increase collagen production in the dermis (deep supporting layer of the skin) and stimulate the production of hyaluronic acid, a mucopolysaccharide with superb water binding ability.

The advantage of AHAs is that, unlike tretinoin (vitamin A acid), they do not cause photosensitivity, are relatively non-irritating and can be used by pregnant women and women who are breast feeding. In terms of effectiveness, however, they nowhere near tretinoin. The activity of AHAs is very dependent on the pH. Most AHAs are only effective at a low pH of between 2.8 - 3.5. However, low pH formulations can irritate the skin so many AHA products overcome this problem by buffering. Unfortunately, doctors believe that buffering reduces their effectiveness. A 15% concentration with a pH of 5 may therefore, be less effective than a 8% one of pH 3. Unfortunately, the pH is often not indicated on the label. Generally speaking, over-the-counter AHA creams meant for the mass market are not as strong as those prescribed by doctors. AHAs are also used by doctors as a superficial chemical peel agent (see chemical peels).

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Antihistamines are drugs which block the action of histamine, the chemical that is released during an allergic reaction and which causes inflammation and itching. Examples of antihistamines include:

• Chlorpheniramine maleate,
• Brohpheniramine maleate,
• Homochlorcyclizine hydrochloride,
• Buclizine hydrochloride,
• Dexchlorpheniramine maleate,
• Pheniramine,
• Promethazine hydrochloride,
• Mequitazine,
• Trimeprazine tartrate,
• Azatadine maleate,
• Cyproheptadine hydrochloride,
• Promethazine hydrochloride,
• Mebhydrolin,
• Hydroxyzine,
• Loratidine,
• Ebastine,
• Cetrizine.

The last four antihistamines are newer and do not enter the brain and do not usually cause drowsiness. Other possible side effects include dizziness, appetite loss, nausea, dry mouth, blurry vision and problems with urination. You should not drive or operate heavy machinery if you are affected by drowsiness.

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Beta-hydroxy acids or BHAs are not widely known even though one of them, salicylic acid has been used in wart and acne medicines much longer than AHAs. They work like AHAs in dissolving the cement between the dead skin cells and exfoliating them. However, unlike AHAs, salicylic acid is lipid (fat) soluble and penetrates the skin better. It is therefore, effective in lower concentrations that are even less irritating than AHAs.

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Botulinum toxin (Botox ) is a bacterial nerve toxin capable of causing fatal food poisoning. In minute quantities, however, botulinum toxin has been used by doctors for treating blepharospasm, a condition causing twitching of the eyelid muscles and other types of muscular spasms. It was during treatment of blepharospasm that doctors noticed the loss of wrinkle lines. Since, then the botulinum toxin has been used successfully and safely to treat dynamic wrinkles such as forehead frown lines and crow's feet. The botulinum toxin paralyses or weakens the muscles that pull on the skin, hence reducing the lines and furrows.

The toxin comes in a freeze-dried form and has to be reconstituted and diluted. Minute quantities of the botulinum toxin is injected directly into the muscle and the procedure is not very painful. However, beneficial effect lasts only about 3 - 6 months after which treatment needs to be repeated. One possible complication is a droopy eyelid or eyebrow which is temporary, lasting 2 - 3 months.

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Chemical peels involve the application of chemicals to wound the skin to a desired depth so that with healing, wrinkles, irregularities of contour and pigmentation become less prominent. In other words, old imperfect skin is removed, unveiling a fresher, clearer, smoother looking complexion. Chemical peels are usually performed on the face where the good blood supply aids healing. Many doctors prescribe tretinoin (vitamin A acid) creams for 2 - 6 weeks prior to peeling as this seems to improve healing, especially after medium-depth and deep-depth peeling. If there is a risk of pigmentation, hydroquinone (a skin lightening) cream is sometimes also included.

Conditions that may benefit from chemical peels

• Wrinkles (rhytides).
• Hyperpigmentation or uneven pigmentation.
• Sun-damaged skin.
• Actinic lentigines (age spots).
• Solar keratoses (precancers).
• Seborrhoeic keratoses (age warts).
• Scars - for example, acne scars (but not the ice-pick variety which should be excised first), chickenpox scars, surgical and traumatic scars.
• Acne vulgaris..

The recovery after medium and deep-depth chemical peeling is hastened and the risk of developing postinflammatory hyperpigmentation (increased pigmentation) can be reduced by using tretinoin and hydroquinone lightening creams, respectively, 2 - 6 weeks before the procedure. Different chemicals penetrate the skin to different degrees. Generally, the higher the concentration the greater the penetration with the sole exception of phenol which is stronger when diluted. Chemical peels are classified into three types:

• Superficial chemical peels.
• Medium-depth chemical peels and.
• Deep-depth chemical peels..

Superficial peels
Superficial peels penetrate the epidermis predominantly or may extend slightly into the papillary dermis. Multiple peels (3 - 6 peels) are necessary to induce the production of collagen. The discomfort is mild so no anaesthesia or sedation is necessary. Recovery is also very fast, hence they are sometimes also called "office-peels" and serious complications are rare. Superficial peels are suitable for all skin types.

Agents used

• 10 - 20% trichloroacetic acid (TCA).
• Alpha-hydroxy acids (AHAs) - glycolic acid, lactic acid.
• Jessner's solution (contains salicylic acid, lactic acid and resorcinol).

  Benefits

• Improve the texture of sun-damaged skin.
• Improve fine lines and mild wrinkles.
• Improve uneven pigmentation.
• Reduce pore size.
• Improve acne vulgaris (pimples) and oily skin.

Medium-depth peels
Medium-depth peels penetrate into the papillary dermis and upper reticular dermis. The benefits are more pronounced than multiple superficial peels and one or two peels are usually sufficient. Medium-depth peels are very suitable for skin phototypes I and II. They can also be used in darker skin types but patients have to be warned about the possibility of temporary hyperpigmentation (especially in skin phototypes III and IV skins) which may require treatment with hydroquinone-containing lightening creams. Although, medium-depth peels are more painful than superficial peels, anaesthesia is usually not necessary. Oral or occasionally, intramuscular sedation may be used in patients who are very anxious or have a low pain-threshold. The only exception is the medium-depth phenol peel which requires the same sedation or anaesthesia as the deep-depth phenol peel (see the next section).

Agents used

• Full-strength phenol (88%).
• Trichloroacetic acid (TCA) 35 - 45%.
• Combination peels
  
  
  • Jessner's solution and TCA 35%.
  • Glycolic acid and TCA 35%.
  • Solid carbon dioxide and TCA 35%.

  
  Benefits

• Improve mild to moderate wrinkles.
• Improve mild to moderate sun-damage.
• Improve uneven pigmentation.
• Remove solar keratoses (precancers).
• Improve mild scars.

Deep-depth peels
Deep-depth peels penetrate to the mid-reticular dermis. Only one peel is sufficient and microscopic studies suggest that the benefits of deep-depth phenol peels may last as long as two decades. However, phenol is a toxic chemical so full blood counts, liver and kidney function tests, urine tests and an electrocardiogram (ECG) of the heart must be done before the procedure. Pain is severe so general anaesthesia or nerve blocks alone or with intravenous (IV) sedation is necessary. The electrocardiogram (ECG), blood pressure and blood oxygen must be monitored throughout the procedure. Hypopigmentation (lightened skin) is common after deep-depth peeling so this treatment is not very suitable for people with skin phototypes IV - VI. Deep chemical peels are being replaced by laser resurfacing which does not have toxicity problem of phenol.

Agents used

• Baker's formula phenol peel (50%).
• Trichloroacetic acid (TCA) 50% is rarely used.

  Benefits

• Improve moderate to severe wrinkles, especially those around the mouth.
• Improve blotchy and sun-damaged skin.
• Remove solar keratoses (precancers).
• Improve scars.

How long do the benefits of a chemical peel last?
It is important to understand that the effects of a chemical peel will not last forever because the ageing process will continue. Dr Albert Kligman who did the pioneering work on tretinoin studied women who underwent deep phenol peels and then facelifts 1 1/2 to 20 years later. He examined the excess skin removed during the facelift and noticed striking differences between the peeled and unpeeled skin. The epidermis was more normal in appearance, melanin was more evenly distributed and there was no microscopic evidence of actinic lentigines (age spots) and solar keratoses (precancers) in the peeled skin. The dermis also showed evidence of new collagen and elastin tissue on top of a disorganised mass of deeper, presumably unpeeled dermis. These findings suggest that the benefits of a deep phenol peel may last as long as 2 decades (average of 5 - 7 years). There are no data on the duration of benefit from medium-depth peels but most doctors estimate that they last 1 - 2 years. The benefits of multiple superficial peels, last only about 6 months so superficial peels have to be repeated.

What to do before a chemical peel
You must fully understand what the peel involves, what reaction to expect after the peel and how to look after the peeled skin. Much of this should have been provided by the doctor or his assistant but do not be afraid to ask until you are clear about this.

Chemical peels are usually performed as outpatient procedures. Clean your face with soap and water and do not apply any cosmetics for 24 hours prior to a peel. Arrange for transport and someone to accompany you home after medium- or deep- depth peels because the swelling may close your eyes and if sedation is used. This is not necessary after a superficial peel. You should also not eat or drink for at least 6 hours before the procedure if you are having a general anaesthesia or IV sedation.

Anaesthesia and sedation

• Superficial peels - Anaesthesia and sedation is usually not required.
• Medium-depth trichloroacetic acid peels are more painful - Oral or intramuscular sedation may, occasionally, be used if the patient is very anxious or has a low pain threshold.
• Deep-depth phenol peels - Phenol peels are much more painful and require general anaesthesia, local anaesthesia or nerve blocks alone or with intravenous (IV) sedation. An anaesthetist will be present when general anaesthesia is used and a qualified nurse or an anaesthetist when IV sedation is used. The ECG (heart tracing), blood pressure and blood oxygen need to be monitored during phenol peels.

Peel application
In the clinic, you will be asked to lay down on a couch with the head slightly raised so that the peel solution will not get into the eyes. You will probably be asked to put on a protective gown or sheet and a hair-band may be used to keep the hair away from the face. The doctor or his assistant begins by cleaning the skin with a pre-peel cleanser or a degreasing agent such as alcohol or acetone to remove surface oil and ensure uniform penetration of the peel agent. The chemicals most commonly used for superficial, medium- and deep-depth peels are glycolic acid (an alpha-hydroxy acid), trichloroacetic acid (TCA) 35 - 45% and Baker's formula phenol, respectively. The method of application, post-peel course and after-care are described in greater detail below.

Superficial peel with glycolic acid 20 - 70%

• The peel solution is applied with a brush, cotton-tip applicator or gauze.
• It is left on for 3 - 6 minutes before neutralising with water or a solution containing 1% sodium bicarbonate.
• You will then be asked to rinse your face with cool water until any stinging sensation subsides.
• Your skin is cleansed once again with the neutraliser to remove residual acid.
• A small amount of soothing cream is then applied to your face.
• A small hand-held fan or dry ice pack may be used to reduce the mild burning discomfort.
• The entire procedures takes only about 10 minutes to perform.
• Peeling has to be repeated for 4 - 6 times at 2 - 4 weekly intervals until the desired result is obtained.
• The depth of peeling depends on the concentration and the time the solution is left on the skin before neutralising. With subsequent applications, either the concentration of the peel solution or the time it is left on the skin is increased.
• The main advantage of glycolic acid peels is the short recovery time. Reactions are mild, ranging from a sunburn appearance to slight weeping and crusting and short-lived. Glycolic acid peels are often called "lunch-time peels" or "office peels" because the patient may even return to work immediately after the peel.
• The after-care is very simple.

   

Medium-depth peel with trichloroacetic acid 35 - 45%

• Trichloroacetic acid (TCA) is usually applied with a piece of folded gauze or sponge and a cotton-tipped applicator near the eyes. Some doctors use cotton-tip applicators as in a phenol peel for the entire face.
• A frost appears within a few minutes of application and this is accompanied by immediate tightness, warmth and stinging. The discomfort is usually severe for about 10 minutes and then subsides. It can be relieved by applying a cool compress or a dry ice pack.
• The doctor may apply a dressing to reduce post-peel discomfort or he may use an open dressing method which involves soaking the face with cool water several times a day followed by application of vaseline or an antibiotic ointment.
• The TCA peel takes about 15 minutes to perform.
• A touch-up peel may be performed after 6 months, if necessary.
• Unlike glycolic acid, TCA peels do not need to be neutralised. The depth of wounding is related to the strength of the TCA and not the time it is left on the skin.
• The recovery period is longer and patients may have to remain homebound for about 1 week.
• The after-care is extremely important in order to avoid complications.

   

  Deep-depth peel with Baker's formula phenol

• The peel solution is applied with one to three regular cotton-tip applicators. To avoid toxicity, the doctor divides the face into 6 - 8 segments, applying phenol slowly over 15 - 20 minutes to one segment at a time. Phenol is not used on the eyelids. Dilution of phenol by tears increases its potency so an assistant is at hand to soak up any tears with a dry cotton applicator.
• The skin develops a frost very rapidly, within seconds of the application.
• The doctor may tape the skin for the first 24 - 48 hours to increase penetration or apply an antibiotic ointment or vaseline.
• As with TCA peels, the after-care is extremely important.
• You may be hospitalised for 1 - 2 days after a full-face phenol peel.

Generally, the peel application is applied a little over the hairline, borders of the lips, under the jaw and upper edge of the neck to avoid creating transition lines between peeled and unpeeled skin. Tears rolling down the cheeks can dilute the peel solution causing a streaked appearance. In the case of phenol, dilution increases the strength of the peel causing a deeper wound than is intended. An assistant is therefore, at hand to soak up tears with a cotton-tip applicator.

Post-peel course and after-care
It is very important that you understand the changes that occur after a peel so that you are not too alarmed. The after-care is especially important after medium- and deep-depth peels and will be reiterated to you or the person looking after you. Handouts may be given and you should consult the doctor or his nurse whenever you are unsure.

Care of the skin after glycolic acid superficial peel

• There is immediate redness after application of glycolic acid peel solutions which lasts less than an hour.
• Slight redness, dryness and peeling of the skin may occur, generally lasting less than 4 days.
• The irritation is mild and can be reduced with the application of a cold compress or a dry ice pack.
• Healing occurs after 2 - 4 days.
• A soothing cream is usually prescribed until the skin has healed.
• You can return to work almost immediately and wear cosmetics after 24 hours.
• Avoidance of the sun is the main requirement and sunscreens should be used during daylight hours and preferably, for life in order to delay ageing.
• You can start to use the prescribed medicines such as glycolic acid creams or tretinoin cream once the skin has healed which is usually between 3 - 7 days.
• The peel can be repeated after 2 weeks for a total of 4 - 6 times in order to achieve a smoother, brighter complexion.
• The benefits last less than 6 months.

   

  Care of the skin after a medium-depth TCA peel

• Immediately after the TCA peel, the skin is red and may be slightly swollen.
• Most of the pain is felt during the application itself but if it continues, use cold compresses and dry ice packs. Over the first 2 days the skin becomes deeply tanned and the tanned skin will peel of as a membrane afterwards. It is usually possible to return to work after 7 days.
• As in superficial peels, it is very important to use sunscreens and avoid unnecessary exposure to the sun.
• The benefits lasts about 1 - 2 years.

   

  Care of the skin after a deep-depth phenol peel

• The reaction after a phenol peel is more severe.
• The skin begins to swell within a few hours and the swelling usually shuts the eyes. Sleeping with the head slightly elevated helps to reduce the swelling.
• Ice packs can be applied (over the dressing, if necessary) and a simple painkiller such as paracetemol may be taken to reduce the discomfort. The dressing, if used, is usually removed after 1 - 2 days.The skin usually looks raw and weepy like a second degree burn.
• Rinse the face with cool water or apply wet compresses several times a day followed by application of the antibiotic ointment or vaseline provided.
• The aim is to keep the area moist and to soften and gently remove crusts that would otherwise serve as a medium for bacterial growth.
• Healing occurs 10 - 12 days after a phenol peel.
• The benefits last 5 - 7 years.

General measures
Despite counselling by the doctor and/or his assistant, it is not uncommon for patients to experience variable degrees of anxiety after chemical peels. This is quite natural and you should not hesitate to contact your doctor or his assistant if you are in any way worried. The following are some general measures you can take to help your face recover quickly:

General post-peel measures

• Do not pick or peel off the skin. Loose skin can be trimmed with a sharp pair of scissors.
• Pat dry, do not rub the skin.
• Avoid scrubs and abrasive sponges such as Buf-puf as the skin is very sensitive at this stage.
• Avoid astringents and toners until advised otherwise by your doctor.
• Do not scratch. Ask the doctor for some antihistamine tablets if itching is a problem.
• Take a simple painkiller such as paracetemol for pain relieve and inform the doctor if the pain is not relieved.
• Avoid excessive exertion and alcohol which would increase blood flow to the skin and encourage the development of telangiectasias (broken capillaries) for at least 2 weeks after surgery.
• Avoid excessive talking, laughing and chewing after deep-depth peels.
• Take a liquid diet if the mouth is very swollen.
• Avoid excessive exposure to sunlight and use a broad-spectrum sunscreen until the redness has cleared and the skin has regained its normal colour. Sunscreens should be used indefinitely thereafter, to prevent further sun-damage.
• Moisturise the skin regularly with the cream provided. You can resume application of your prescribed creams after the skin has resurfaced but remember that the skin will be more sensitive than usual.
• Make-up can be applied to areas of skin that has resurfaced but remember that the skin is more sensitive after chemical peels. If irritation occurs, discontinue it.
• Avoid contact sports where there is a risk of bumps or injury to the skin for at least 6 weeks.
• Contact your doctor if there is redness, tenderness and a pus-like discharge from the skin. It may indicate bacterial infection which may require antibiotic treatment.
• Contact your doctor if the skin becomes red, raised and itchy after it has apparently healed as this may indicate the development of lumpy scars (keloids).
• Contact the doctor immediately if blisters appear because it may indicate a recurrence of herpes labialis or "cold sores".

Complications
Complications are generally rare and can usually be treated and reversed.

• Pigmentary changes
  People with skin phototypes I - II skins are ideal for chemical peels. Darker skinned individuals are more at risk of developing pigmentary problems like hypopigmentation (lightened skin) or postinflammatory hyperpigmentation (darkened skin). Hypopigmentation is common after deep-depth or phenol peels which is why they are generally avoided in people with skin phototypes IV - VI, especially men because they cannot wear make up. It may occur temporarily with more superficial other peels. Hyperpigmentation may occur after superficial and medium-depth chemical peels in darker skinned individuals, especially type III and IV skin phototypes. Hyperpigmentation can be treated with lightening creams and may be averted by putting susceptible individuals on hydroquinone lightening creams before peeling and after the new skin has resurfaced.
• Scarring
  Superficial peels are generally safe. Medium- and deep- depth peels may occasionally produce scarring and should be avoided in people with a tendency to develop abnormal or lumpy scars (keloids). Scarring has been reported after isotretinoin treatment which is why medium and deep -depth peeling should only be done 12 - 18 months after completion of isotretinoin treatment.
• Infection
  Bacterial, yeast and viral infections may occasionally occur. Bacterial infections occur but are generally uncommon. Presumably, this is because the peel agents themselves sterilise the surface of the skin and there is a good supply of blood to the face. The risk of infection can be reduced by soaking off crusts that may otherwise provide a rich media for bacterial growth and by following the doctors after-care instructions carefully. Bacterial infections can be treated with oral antibiotics. Deep chemical peels may reactivate herpes labialis (cold sores) and cause scarring. Patients with a past history of herpes labialis are usually prescribed an anti-herpes drug such as acyclovir or famcyclovir 24 hours before and continued for a total of 7 - 10 days to prevent a recurrence.
• Milia
  These are tiny "whiteheads" formed when the new skin grows over. They usually occur 2 - 3 weeks after the skin has resurfaced and can be extracted by the doctor with a number 11 scalpel blade.
• Systemic side effects
  This complication applies only to phenol peels. Unlike other chemicals, diluted phenol actually penetrates deeper than full-strength phenol and may enter the blood circulation to produce toxic effects. The main effect is on the heart which may result in heartbeat irregularities. This is why phenol must be applied slowly over one segment at a time to allow the body to clear the phenol and prevent the accumulation of toxic levels of phenol. The electrocardiogram (ECG), blood pressure and blood oxygen must be monitored during application of phenol. Blood test and urine tests have to be done before a phenol peel to assess the function of the liver and kidneys, both of which participate in the metabolism and excretion of phenol.
• Poor patient physician relationship
  Patient dissatisfaction is a common complication and may be caused by the doctor's failure to understand the patients desires or unrealistic expectations on the part of the patient.

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Compresses may be of two types - dry compresses and wet compresses. Dry compress may use cold (cold compresses) to relieve a very swollen area or heat (warm compresses) to bring an abscess such as a furuncle to a point and aid drainage. Wet compressed or wet dressings use gauze or some other absorbent material soaked in water, saline, Burrow's solution or diluted potassium permanganate solution. They are useful for weeping and crusted areas or . Wet compresses are applied on the area for 20 - 30 minutes two to four times a day. Evaporation soothes and dries the area.

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Corticosteroids or steroids for short are a group of synthetic hormones similar to those produced by the adrenal glands sitting on top of the kidneys. They have strong anti-inflammatory properties and are useful in the treatment of inflammatory disorders such as eczema and psoriasis. Steroids are divided into the following groups depending on how they are used:

• Topical steroids which are externally administered, eg., creams, lotions, ointments and sprays. To increase penetration occlusion is sometimes used. Occlusive therapy, as this method is called, uses an occlusive dressing or household polythene wrap.
• Systemic steroids which go into the general circulation and reach all parts of the body, eg., oral steroids (taken by mouth), intramuscular steroids (injected into muscles) and intravenous steroids (injected into veins).
• Intralesional steroids which are injected into a chronic or resistant skin abnormality such as prurigo nodularis, lichen simplex chronicus or keloids or into acne cysts.

  Side effects
  Steroids are extremely useful and their benefits far outweigh the risks when used properly. Side effects may be divided into local and systemic side effects:
  
  

• Local side effects
  This may occur with topical and intralesional steroids.

   

  • Atrophy (thinning of the skin).
  • Striae distensae (stretch marks) due to reduced synthesis of collagen.
  • Lightening of the skin.
  • Telangiectasias (broken capillaries)
  • Purpura (bruising).
  • Hypertrichosis (increased hairiness).
  • Infections may be made worse by steroids.
  • Acne rosacea.
  • Perioral dermatitis.
  • Acne vulgaris.

   

• Systemic side effects
  These may occur with systemic steroids and very occasionally may be caused by increased absorption through the skin when strong topical steroids are used under occlusion or over large areas of skin.

   

  • Immune suppression.
  • Diabetes.
  • Stomach ulcers.
  • Hirsutism (facial hair).
  • High blood pressure and heart failure due to salt retention.
  • Osteoporosis (thinning of the bones).
  • Muscle weakness, especially of the shoulder and hip muscles.
  • Stunting of growth in children.
  • Eye problems such as cataracts and glaucoma.
  • Redistribution of fat - accumulation of fat on the face (moon face), below the back of the neck (buffalo hump), truncal obesity and reduction of fat in the limbs.
  • Cushing's syndrome.
  • Psychological problems such as insomnia (inability to sleep), mood changes and even psychosis.
  • Adrenal suppression - prolonged use of systemic steroids may suppress the body's own production of steroids. These steroids are needed for the body's response to stress. Shock and coma may develop when systemic corticosteroids are stopped suddenly. This is why doctors taper off the dose slowly.

   

  Guidelines on the proper use of topical steroids on the skin

• Apply only on the affected areas.
• Different strengths of steroids are used on different sites (milder steroids are used on the face), for different severities (milder steroids are used for milder problems) and for different ages (milder steroids are generally used in infants and young children). Understand and follow the doctors instructions, do not mix them up.
• Do not use steroids on areas other than they are intended as they can make the problem (especially infections) worse.
• Do not oversuse steroids.

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Finasteride is a new treatment for androgenetic alopecia (male pattern baldness). It works by inhibiting the 5-alpha reductase enzyme that converts testosterone to dihydrotestorone (DHT). DHT is believed to suppress hair follicle activity so that hair growth is retarded until eventually only a fluff of hair is produced. Finasteride is taken orally at the dosage of 1mg per day. It takes about 6 months before any improvement can be seen and treatment must be continued or the newly grown hairs will fall out. Finasteride cannot be used in women that are or may become pregnant because it may cause genital abnormalities in male babies. In clinical trials comparing finasteride with placebo (dummy pills), a small but slightly higher number of men treated with finasteride noticed loss of libido (sexual drive), erectile dysfunction and smaller volume of sperm. However, all side effects resolved when finasteride was discontinued.

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Medical treatments of androgenetic alopecia (male pattern baldness) with minoxidil applications or finasteride tablets are effective only as long as the medication is continued and hair will fall out once the medication is stopped. For those who desire a more permanent solution and for those with severe androgenetic alopecia, hair replacement surgery offers an alternative. Hair replacement surgery may be divided into three main types which may be combined to produce the best results.

• Hair transplantation.
• Flap surgery.
• Scalp reduction.

  Hair transplantation
  The hair at the back of the head are not affected by androgenetic alopecia and can be relocated to the bald areas. This can be done in two main ways - by removing grafts of hair-bearing skin from the back of the head and inserting them in holes or slits created in the bald area. The grafts differ in size and shape according to the method used. Punch grafts are round and usually contain 10 - 15 hairs, mini-grafts contain 2 - 4 hairs, micro-grafts 1 - 2 hairs, slit-grafts 4 - 10 hairs and strip grafts 30 - 40 hairs. The transplanted grafts retain the characteristics of the hairs at the back of the head and are not affected by the androgenetic alopecia. Hair transplantation is time consuming and several sessions are necessary before the final result can be seen. The new hairline is created and larger grafts are transplanted during the initial session. The spaces between are filled in by smaller grafts during subsequent sessions. The number of grafts transplanted depends on the technique used, varying from 50 up to 700 per session. Care is taken by the doctor to orientate the grafted plugs so that the hairs will grow out in a natural direction. The holes created in the back of the head are closed by stitches. The scars are usually concealed by the hair.

  Flap surgery
  Flap surgery involves removing a flap of skin in the bald area and creating a flap of hair-bearing skin that is slid across and stitched into place, leaving one end still attached together with its blood supply. Flap surgery allows large areas of hair to be relocated but is technically more difficult.

  Scalp reduction
  This is a method to reduce the size of the bald patch rather than replace hair. In scalp reduction, a section of the bald scalp is removed and the surrounding skin is undermined (freed from its deeper attachments) so that the edges can be brought together and stitched. The procedure also gives the forehead a slight lift. Doctors now combine different techniques and use tissue expanders (a balloon-like device that is inflated with saline to cause the skin to expand) to stretch the skin so that larger sections of bald skin can be removed. Hair replacement surgery is usually done under general anaesthesia or local anaesthesia with IV sedation.

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These are drugs used to suppress the body's immune system. Immunosuppressive drugs include corticosteroids which was described earlier and cyclosporin (used to prevent organ rejection in transplant patients) and some anti-cancer drugs. Immunosuppressive drugs are sometimes used to treat skin disorders such as scleroderma, pemphigus, bullous pemphigoid, lupus erythematosus, dermatomyositis, pyoderma gangrenosum, Wegener's granulomatosis, some types of vasculitis, mycosis fungoides, and even severe cases of atopic dermatitis, psoriasis and alopecia areata. Examples of immunosuppressive drugs include:

• Azathioprine.
• Hydroxyurea.
• Methotrexate.
• Cyclophosphamide.
• Cyclosporin (used for treating organ rejection) is sometimes used to treat severe atopic dermatitis, psoriasis, alopecia areata, ichthyosis vulgaris, epidermolysis bullosa acquisita, pyoderma gangrenosum, systemic lupus erythematosus, cutaneous T-cell lymphoma, sarcoidosis.Treatment must be closely supervised and regular blood, urine tests and blood pressure measurements are necessary. Side effects include hypertension, kidney problems, increased hair growth, nausea and loss of appetite, swollen bleeding gums and pins and needles.

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Implants are synthetic or natural materials that are implanted into the skin to improve the facial contour or raise depressed or sunken scars and puff up wrinkles. There are two varieties of implants - solid implants and injectable implants:

• Solid implants
  Solid implants are used to enhance the facial contour, for example to strengthen the jawline or augment the cheek (known medically as malar augmentation) or chin (mentoplasty) or reshape the nose (rhinoplasty. Local anaesthesia with or without sedation or general anaesthesia may be used. In chin augmentation for example, an incision is made along the lower lip or under the chin and the implant is inserted into a pocket created in front of the jaw bone. For cheek implants, an incision is made inside the mouth through the lower eyelid or behind the hairline. Recovery may take 5 - 10 days, depending on the procedure. A variety of implants may be used including bone, cartilage or silicone.
  
• Injectable implants (filler techniques)
  Injectable implants, as the name suggests are injected into the skin to puff out wrinkles and raise depressed or sunken scars with sloping edges (scars with well-defined steep edges do not respond well). The material used for implants include collagen purified from cattle skin, a material known as Fibrel, the patient's own fat or a synthetic material known as Gortex but NEVER liquid silicone.

   

  • Collagen is injected into the dermis and is available as Zyderm I and II and Zyplast. Zyderm collagen is less concentrated and is injected into the upper layers of the dermis. It can be used to correct superficial wrinkles on the forehead, superficial or secondary creases adjacent to nasolabial furrows, forehead creases, vertical creases around the lips which cause lipstick to "bleed" and "crow's feet" on the outside of the eyes. Zyplast collagen is more concentrated and is injected into the mid to lower layers of the dermis. It is used to correct deep wrinkles, nasolabial furrows which run from the corners of the nose to the chin and deep distensible scars (scars that are effaced when stretched) and for lip augmentation (puffing the lips that are thinned and have lost their fullness or pout). Zyplast cannot be used for treating deep forehead wrinkles because there have been reports of it causing skin necrosis there. How long the benefits of an implant lasts depends on the mobility of the region. When used on a relatively immobile areas such as acne scars, the benefits of an implant can last about 6 - 18 months. If the area is very mobile for example deep forehead wrinkles and deep nasolabial furrows, the effect may last only 3 - 12 months. Crows feet can last up to 1 year. Lip augmentation may only last 6 weeks. A skin test has to be performed by injecting a small amount of collagen into the patient's forearm and checking the site at 48 - 72 hours and then at 4 weeks. This helps to detect allergy which occurs in about 3% of individuals. Very occasionally, allergy may still develop in those whose skin tests are negative. There is also concern that collagen might increase the risk of autoimmune disorders (self-allergies) such as lupus erythematosus, polymyositis/dermatomyositis developing. Collagen implants cannot be used in pregnant women, people allergic to lignocaine (the anaesthetic agent that is mixed in with the collagen implant) or beef and in those with a history of autoimmune disorders (self-allergies) such as lupus erythematosus and rheumatoid arthritis.

   

  • Fibrel contains three components - a powdered gelatin made from porcine (pig) collagen, aminocaproic acid and the patient's own plasma. Plasma is prepared from the patient's own blood which means the doctor will have to draw blood from the patient's arm. This is then centrifuged to separate out the plasma which is then mixed with the gelatin and aminocaproic acid. The mixture is then injected into the dermis. Fibrel is useful for treating deep wrinkles and distensible scars, not the more superficial facial lines. A skin test is still needed to detect allergy even though this is less common than with collagen implants. Fibrel injections tend to be more painful and the procedure takes more time to perform and causes more bruising than collagen implants. It is therefore, not as popular.

   

  • Fat liposuctioned from the abdomen, buttocks or thighs can be injected into the skin to replace fat lost through ageing, puff up wrinkles and scars and to restore fullness to thin lips. There is no risk of allergy since the fat comes from the same person. The technique is known as autologous fat transplantation. Fat cells are washed and decanted. 20 - 30% of cells will take, the others cells are absorbed. In a modification of this procedure, called autologous collagen transplant, collagen is extracted from the liposuction fat and this is then injected. A US based company performs the extraction of collagen so this technique is not available elsewhere. The benefits are similar to those of cattle collagen except that there is no risk of allergy since the collagen comes from the same person.

   

  • Gortex is not truly an "injected" implant but is included here for convenience. It is a synthetic implant which has been used for many years in cardiovascular and renal transplant surgery to serve as a channel between the organ and the arterial supply and in surgery to repair hernias. Recently, it has been used as a facial implant to augment or plump up lips and to correct nasolabial furrows which run from the corners of the nose to the chin and forehead furrows. In nasolabial augmentation, for example, the strip of Gortex is introduced with a needle and threaded underneath the skin. The entry and exit points are then closed with absorbable sutures. The implant does not dissolve and stimulates the production of fibrous tissue which further augments the implant. The procedure is usually done under local anaesthesia. It is generally safe. Complications are uncommon and include infection, irritation and rejection. Another similar but newer technique employs SoftForm which comes as a round, spongy tube with a hollow core. It is used in much the same way as Gortex and is quite good for softening the laugh lines around the mouth and the from the corner of the mouth to the chin.

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These are injections of steroids given directly into swellings such as keloids and inflamed nodules and cysts due to acne vulgaris. The injection is given through a very fine needle and causes a momentary stinging sensation.

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LASER is an acronym for Light Amplification by Stimulated Emission of Radiation. Lasers use high intensity light of a specific wavelength to cut, burn, coagulate (eg., blood vessels) or fragment (eg., melanin or tattoo pigment).

The laser consists of an optical cavity or laser tube containing the active medium (the source of the laser radiation) which may be liquid (as in the flashlamp pumped dye laser), solid (as in the Neodynium-Yttrium-Aluminium-Garnet or NdYag and Alexandrite lasers) or gas (as in the carbon dioxide or CO2 laser), and a power source to excite the atoms in the active medium. In accordance with the laws of photophysics, excited atoms are unstable and will return spontaneously to a more stable lower energy state. When these atoms return to their steady state, they emit photons of energy. Because there are thousands of atoms in the excited state they tend to bump into one another transferring energy to the other. Eventually some of the atoms reach energy levels that exceed the threshold of a partially silvered mirror at one end of the laser tube and are emitted as a high intensity laser beam which can be used to destroy tissues and even cut metals in industries.

There are many different types of lasers named after the active medium used and the choice of laser depends on the type of tissue being treated. Lasers may be classified into selective and non-selective lasers:

 

• Selective lasers
  In the skin there are various chromophores (light attracting structures) such as oxygenated haemoglobin and pigment (eg., melanin or tattoo pigment) which absorb light of certain wavelengths. It is possible therefore, to use lasers emitting light of a wavelength that is absorbed by these chromophores to "smart bomb" or selectively destroy these targets. These lasers are therefore, termed selective lasers. Examples include:

   

  • Vascular lasers

     

    • Flashlamp pumped dye (585nm) laser
    • Variable pulse width NdYag (532nm) laser

     

  • Pigment lasers

     

    • NdYag (532nm & 1064nm) laser
    • Alexandrite (753nm) laser

     

• Non-selective lasers
  Sometimes the chromophore is present in all living cells like water. Lasers that target water will therefore, destroy anything in its path. Such lasers are termed non-selective lasers. Examples include:

   

  • Carbon dioxide laser (10,600nm)
  • Erbium Yag laser

The carbon dioxide laser can be used for cutting or burning skin growths. More recently, CO2 lasers have been introduced which are capable of producing a very high energy output in short pulses of as little as 1 millisecond. The high energy allows tissue to be destroyed in a shorter time - milliseconds so that less heat is transferred to the surrounding tissue, minimising the risk of scarring. These high energy pulsed lasers are known as superpulsed or ultrapulsed lasers. The superpulsed and ultrapulsed CO2 lasers have now been fitted with computerised scanners which move the laser beam rapidly over the skin so that the time the laser beam dwells on one particular spot is short and even less heat is generated and consequently even less risk of scarring. These lasers can remove layers of skin as little as 50 - 100 microns at a time and can be used in more or less the same way as chemical peels and dermabrasion to treat wrinkles and scars (see laser resurfacing). The Erbium-Yag laser removes even thinner layers of skin (25 microns) and its main use is for laser resurfacing.

Selective lasers are generally less painful and the application of an anaesthetic cream 60 - 90 minutes beforehand will usually suffice. Non-selective such as the carbon dioxide and Erbium-Yag lasers however, are more painful and anaesthetic injections are usually required. The different types of lasers and their uses are summarised below:

Class of laser	Examples	Uses
Vascular lasers	Flashlamp pumped dye laser (585nm) Variable pulsed width NdYag laser (532nm)	Vascular birthmarks Telangiectasias (broken capillaries) Small varicose veins
Pigment lasers	NdYag laser (532nm)	Red tattoos
	NdYag laser (1064nm) Alexandrite laser (755nm)	Pigmented birthmarks Blue, black and green tattoos
Non-selective lasers	Carbon dioxide laser (10,600nm)	Skin resurfacing. Cutting and vapourising (burning)
	Erbium Yag laser	Skin resurfacing.

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The workings of lasers were explained in the previous section. The carbon dioxide and Erbium-Yag lasers can both be used to burn away thin layers of skin. This technique, known as laser resurfacing or "laser peeling" works like chemical peels and dermabrasion. The carbon dioxide laser is more deeply penetrating than the erbium-yag laser which removes 25 micron layers of skin compared to 50 - 100 microns by the carbon dioxide laser. Both these lasers come with computerised scanners which scan the laser beam quickly across the skin and allow the skin to be resurfaced quickly with minimal heating of the skin and consequently, minimal risk of scarring. Unlike dermabrasion, laser resurfacing is not hampered by the spattering of blood and tissue and there is not much bleeding to obscure the view. There is also less post-operative discomfort and faster healing. Laser resurfacing is generally more expensive than chemical peels or dermabrasion because of the high cost of laser machines. The depth of penetration increases with the number of passes the laser beam makes over the skin which allows greater flexibility in treating different severity of scarring and wrinkling. The benefits of laser resurfacing last an estimated 5 - 6 years. As with dermabrasion and chemical peels, deep ice-pick acne scars require prior scar revision using punch excision, punch elevation or punch grafting before laser resurfacing for the best results. Remember also that the laser resurfacing only pushes the age clock back, it doesn't stop it entirely. Treatment may need to be repeated.

Benefits

• Improve wrinkles, especially mild to moderate wrinkles and those around the eyes (crow's feet) and mouth.
• Improve nasolabial furrows and forehead frown lines.
• Improve scars caused by chickenpox, surgery and trauma and some types of acne scars.
• Improve sun-damaged skin.

  Pre-treatment
  This is similar to the preconditioning treatment described on page . It has been observed that healing after laser resurfacing is enhanced when the skin has been pre-treated with tretinoin 0.025 or 0.05% nightly so most doctors put their patients on this regimen for 2 - 4 weeks prior to treatment. If hyperpigmentation is anticipated, especially with skin phototypes III and IV, the doctor may prescribe a lightening cream, as well. Patients with a history of recurrent herpes labialis (cold sores) and those having laser resurfacing around the mouth are usually started on antiviral medicines such as acyclovir or famcyclovir one day before surgery and continued for a total of 7 - 10 days.
  
  

  Anaesthesia
  Depending on the extent of the area being treated, general anaesthesia, local anaesthesia or nerve blocks with or without IV sedation may be used.

  
  Laser procedure

  • The face is cleansed with a non-flammable cleanser to remove makeup, oil and dirt.
  • You will then be asked to wear protective goggles. If the area being treated is near the eyes, special eyeshields need to be worn.
  • The wrinkles may be outlined prior to the local anaesthetic injections (because the injections alter their appearance) and the area of treatment delineated.
  • The laser beam is delivered to the skin via a special handpiece which is moved over the treatment area with minimal overlapping.
  • After each pass of the skin, the doctor uses a saline-soaked gauze to wipe away the burnt tissue. A dry gauze is then used to dry the area.
  • Additional passes are made to smoothen out wrinkles and scars, as necessary.
  • The doctor may apply a dressing over the area or he may use an open dressing method involving the application of an antibiotic ointment or vaseline several times a day.

  It takes approximately 45 minutes to treat the areas around the eyes and mouth or 1 1/2 hour to treat the whole face. Laser resurfacing may be repeated after 6 - 12 months, if necessary.

   

  Post-operative course and care
  Lasers produce a second degree burn and the wound must be properly cared for in order to prevent complications.
  

  • Swelling or oedema may be severe especially around the eyes. You should be accompanied by someone if you are not being hospitalised for the first few days. Sleeping with the head slightly elevated for the first 3 - 5 days helps to reduce the swelling.
  • Dry ice packs can be applied (over the dressing, if any) as often as is necessary during the first 3 days and paracetemol can be taken for pain relief. Avoid taking aspirin or aspirin-like drugs.
  • Dressings, if used, are replaced after 24 hours and removed after 48 hours.
  • The skin may be weepy and crusts need to be removed because they form a medium for bacterial growth. Crusts can be removed gently after soaking the skin in cool or tepid water (some doctors advise adding some vinegar) several times a day followed by application of the antibiotic ointment of vaseline. Keep the skin moist at all times as it speeds up the healing process.
  • The newly resurfaced skin is very red and this may last for 2 months or more. The redness can be camouflaged with green foundation, followed by a skin coloured make-up over it.
  • Hydroquinone lightening creams can be resumed after the skin has resurfaced and tretinoin cream 2 - 3 days later.
  • Avoid excessive exposure to the sun and use sunscreens especially when the skin is still red because pigmentation may develop. UV protective sunglasses should also be worn after laser skin resurfacing around the eyes.
  • Avoid strenuous physical activity for at least 5 days and alcohol which may increase blood flow and encourage the development of telangiectasias (broken capillaries).
  • The benefits of laser resurfacing may not be apparent until some 2 - 4 months after surgery so don't despair.
  • Most patients can return to work after the swelling has subsided in 7 - 10 days.

  Complications
  Although laser resurfacing is relatively safe, our skin's ability to heal varies so the outcome is not always predictable. However, serious complications are uncommon.
  

• Redness is expected and is not really a complication of treatment. It lasts 6 -12 weeks after resurfacing. Green cosmetics are good for camouflaging the redness.
• Scarring is uncommon but may occur when the procedure is carried out too deeply or if the wound gets infected. Early indications of the possible development of keloids (lumpy scars) include redness, elevation and itching of the skin after it has apparently healed. Early treatment with steroid creams may reduce the severity. The risk of scarring may be increased in patients recently treated with isotretinoin which is why laser resurfacing is normally performed at least 12 - 18 months after completing isotretinoin treatment. Areas such as the upper lip and jawline are more prone to develop scarring.
• Ectropion (pulling away of the lower eyelid) may occur when laser resurfacing is done too soon after blepharoplasty (eyelid surgery).
• Hypopigmentation (reduced pigmentation) may occur with deep resurfacing.
• Hyperpigmentation (increased pigmentation) may develop people with skin phototypes III and IV. It is usually temporary and can be treated with lightening creams as in melasma together with strict avoidance of sunlight (see melasma). It may be avoided with the use of preconditioning treatment.
• Bacterial infections are rare and can be treated with antibiotics.
• Candidiasis a fungal infection caused by a yeast-like fungus called Candida albicans is a rare complication. It can be treated with antifungal medicines and creams.
• Herpes labialis may recur after laser resurfacing which is why patients with a history of herpes labialis are started on anti-herpes medicines 1 day before resurfacing and continued for a total of 7 - 10 days.
• Milia or tiny whitehead-like cysts may occur transiently. They can be extracted with a number 11 scalpel blade. Pre-treatment of the skin with tretinoin helps to reduce the formation of milia.
• Acne flares may occur and can usually be treated with topical or oral antibiotics.

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Minoxidil is a drug used for the treatment of hypertension. One of its side effects is increased hairgrowth which was why its manufacturer, Upjohn formulated a topical form for the treatment of alopecia (hairloss). It is used for the treatment of androgenetic alopecia in both men and women and for alopecia areata. Topical minoxidil is available in 2%, 3% and 5% strengths. To be effective topical minoxidil must be applied twice a day for at least 4 months. Treatment must be continued or the regrown hairs will slowly fall out again. Other than local irritation, topical minoxidil does not cause any serious side effects.

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Phototherapy uses light for treatment. There are two main forms of phototherapy that are used for treating skin disorders. Special phototherapy units (cabinets) are used and 2 - 3 treatments per week may be necessary for 12 - 24 weeks.

• UVB phototherapy - using ultraviolet B light.
• PUVA (psoralen ultraviolet A) phototherapy - using psoralens (chemicals that make the skin sensitive to UVA) . in combination with ultraviolet A (UVA) light. It involves applying the psoralen about 10 minutes before (topical PUVA) or taking the psoralen 2 hours before shining.

  UVB phototherapy
  

• Uses
  • Psoriasis.
  • Severe or resistant eczemas such as atopic dermatitis and hand eczema.

   

• Side effects
  • Sunburns.
  • Photoageing and increased risk of skin cancers. Regular checkups for skin cancers are necessary.
  • Eye damage such as keratitis or an inflammation of the cornea and cataracts. Special goggles are worn during treatment.

  PUVA
  

• Uses
  • Psoriasis
  • Severe eczemas such as atopic dermatitis and hand dermatitis.
  • Mycosis fungoides, a skin lymphoma.
  • Polymorphic light eruption (PMLE).
  • Vitiligo.

   

• Side effects
  • Burns ranging from a mild sunburn to blistering (topical and systemic PUVA).
  • Tanned skin locally (topical PUVA) or all over (systemic PUVA).
  • Photoageing and increased risk of skin cancers (systemic PUVA). Regular check up for skin cancers are necessary for those undergoing phototherapy.
  • Itching (systemic PUVA).
  • Nausea (systemic PUVA).
  • Skin ageing and increased risk of skin cancers (systemic PUVA). Regular checkups for skin cancers are necessary.
  • Eye problems such as keratitis or an inflammation of the cornea and cataracts (systemic PUVA). Special goggles are worn during treatment.

   

• Precautions to observe whilst undergoing phototherapy (UVA or PUVA)
  • Follow the doctors instructions carefully.
  • Phototherapy increases the risk of photoageing (sun induced ageing) and skin cancers. Protect the skin against natural sunlight and use sunscreens religiously.
  • Wear wrap around sunglasses that protect against UVA and UVB.
  • Inform your doctor if you have sensitivity to the sun or are taking medications, some of which may increase the sensitivity to sunlight.
  • Tell your doctor if you are pregnant. Systemic PUVA is generally not used in pregnant women even though there is no evidence that PUVA affects pregnancy.

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Retinoids refer to drugs derived from vitamin A. There can be classified into topical and oral retinoids.

Topical retinoids

• Tretinoin cream and lotions - used for treating acne vulgaris (pimples) or photoageing.
• Adapolene gel - used for treating acne vulgaris.
  
  Precautions to observe when using topical retinoids
• Use at night because retinoids increase the sensitivity to sunburn. Use more frequently only is instructed by your doctor. Adopolene does not seem to increase the sensitivity to the sun.
• Apply to dry skin. Wait at least 30 minutes after washing.
• Avoid the eyes and mouth.
• Use sunscreens during the day.
• Irritation may occur and acne may get worse during the first 6 weeks of treatment with tretinoin (less common with adapolene) but the skin usually gets used to it. You may use moisturisers if the skin is very dry but choose an oil-free or non-comedogenic one if you have oily skin or acne vulgaris.
• Use mild cleansers and avoid abrasive scrubs.
• Do not use during pregnancy.
• Seek you doctor's advice if you are uncertain about anything.

  Oral retinoids

• Isotretinoin (Roaccutane or Accutaine) - a very effective medication for nodular of cystic acne vulgaris.
• Acitretin (Neo-Tigason) - used for treating disorders of keratinisation such as psoriasis, Darier's disease, pityriasis rubra pilaris, etc.

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Sunscreens, as the name suggest filter or block the sun's ultraviolet light. They can be divided into two groups:

• Physical sunscreens (sunblocks) - Sunblocks block everything out and use opaque particles such as zinc oxide and titanium oxide. These used to be messy to use but many modern sunblocks now use micronised zinc and titanium oxide which are do not leave such an obvious trace on the skin.
• Chemical sunscreens - These use chemicals that absorb light energy and dissipate in an another form which is less harmful.

Many modern sunscreens contain sunscreen chemicals as well as sunblock agents to provide broad spectrum protection. The ingredients commonly used in sunscreens and sunblocks include the following:

UV-B screening chemicals

• PABA and its esters, for example, glyceryl PABA, Padimate O and Padimate A
• Cinnamates such as potassium cinnamate, diethanolamine-p-methoxy cinnamate, octyl-p-methoxy cinnamate.
• Salicylates such as octyl salicylate, omomenthyl salicylate, ethylhexyl salicylate
  

UV-A screening chemicals

• Benzophenones which filter only short-wave UVA, for example oxybenzone, dioxybenzone and sulisobenzone.
• Dibenzoyl methanes which filters both short and longwave UVA, for example butylmethoxydibenzoylmethane (Parsol 1789 or avobenzone), Parsol 8020 and Eusolex 8020.
• Meroxyl SX
  

Physical sunblocks (blocks everything)

• Titanium dioxide
• Zinc oxide
• Iron oxide

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