Transcript Chloasma.ppt

Chloasma (Melasma)
Melasma is an acquired brown
hyperpigmentation that occurs in sunexposed 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 delivery
Hormonal : “oral contraceptive pills”
Sun exposure
Scented 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
Mechanism of pigment formation
UV
Hyperactive melanocytes
Epidermis
Melanocyte
Tyrosine
Tyrosinase
Melanin
Management of Chloasma
1- Discontinuing hormonal contraception
2- Use broad-spectrum very high protection
sunscreen of reflectant type
3-Alternatively, use a make-up containing
sunscreen
Management of Chloasma
1- The most popular depigmenting agent is
hydroquinone (HQ)
2- Topical retinoids such as tretinoin
3- Azeliac acid
4- Salicylic acid cream
5- Glycolic acid and lactic acid, as chemical peels
5- Topical corticosteroids to decrease the
irritation caused by depigmenting agents
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 acid
AZA inhibits tyrosinase activity and may also exert
antiproliferative and cytotoxic effects on the
hyperactive melanocytes
Other treatment
Dermabration
damage to the melanocytes may increase
pigment production and darken the melasma
Laser treatment