Chloasma (Melasma)

Melasma is an acquired brown hyperpigmentation that occurs in

sun-exposed areas of the skin, most often on the face and results from

exposure to sunlight

Etiological factors There is a genetic predisposition to melasma. Triggers include:Pregnancy – the pigment often fades a few months after deliveryHormonal : “oral contraceptive pills”Sun exposureScented or deodorant soaps and cosmetics – a phototoxic reaction

Epidemiology, Course & Prognosis Chloasma in females is more than in males It appears in all racial types, but occurs more frequently in those persons who live in areas of high UV; sun exposure Chloasma: pregnancy mask: overproduction of melanin induced by hormonal factors and amplified by the sun Melasma may disappear spontaneously over a period of months after delivery or after cessation of contraceptive hormones

Tyrosinase

Mechanism of pigment formation

Epidermis

MelanocyteTyrosine Melanin

UVUV

Hyperactive melanocytes

Management of Chloasma

1- Discontinuing hormonal contraception2- Use broad-spectrum very high protection sunscreen of reflectant type 3-Alternatively, use a make-up containing sunscreen

1- The most popular depigmenting agent is hydroquinone (HQ)

2- Topical retinoids such as tretinoin3- Azeliac acid4- Salicylic acid cream5- Glycolic acid and lactic acid, as chemical

peels 5- Topical corticosteroids to decrease the

irritation caused by depigmenting agents

Management of Chloasma

Demelanizing agents:e.g. Hydroquinone (HQ) act by blocking the synthesis of melanin by inhibition of tyrosinase enzyme responsible for conversion of tyrosine to melanin It should be used only when permanent depigmentation is desired as it may lead to irreversible de-pigmentation

Therapeutic Uses:Chloasma of pregnancy and excessive

freckling, vitiligo

Side Effects:

Local irritation (inflammation)Depigmentation at sites distant from the

treated area due to a certain degree of percutaneous absorption

Allergic dermatitis

Tretinoin (retinoic acid) RA inhibits tyrosinase by inhibiting the enzyme’s transcription. In addition,it reduces hyperpigmentation through the induction of desquamation

Side effects: erythema, peeling in the area of application and post-inflammatory hyperpigmentation

This treatment cannot be used during pregnancy

Azelaic acidAZA inhibits tyrosinase activity and may also exert antiproliferative and cytotoxic effects on the hyperactive melanocytes

Other treatmentDermabrationdamage to the melanocytes may increase pigment production and darken the melasma

Laser treatment