Melasma
Melasma is a common acquired hypermelanosis producing symmetrical, irregular tan to dark brown patches on sun-exposed facial skin, driven by ultraviolet exposure, hormonal influence (pregnancy, oral contraceptives), and genetic predisposition, and diagnosed clinically. Strict sun protection with sunscreen and discontinuation of causative hormonal agents is first-line, and topical hydroquinone 4% cream or a hydroquinone-tretinoin-corticosteroid triple-combination cream is added for patients desiring faster lightening.
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What this article covers
- Overview
Acquired hypermelanosis of the face: melasma, also known as chloasma or the mask of pregnancy, is a common acquired condition causing patchy hyperpigmentation of facial skin, occasionally extending to the upper extremities.
- Epidemiology
Reproductive-age women: melasma most frequently occurs in reproductive-age females.
- Risk factors
Ultraviolet (UV) light exposure: UV exposure is a leading driver of new and worsening pigmentation.
- Pathophysiology
Tyrosinase-driven melanin overproduction: the underlying process is overproduction of melanin by cutaneous melanocytes, stimulated by the combined effects of ultraviolet radiation, hormonal signaling, and genetic predisposition.
- Clinical features
Defining pattern: the diagnostic pattern is a symmetrical eruption of ill-defined, tan to dark brown reticulated patches on sun-exposed facial skin, most often the forehead, malar (cheek)…
- Differential diagnosis
Postinflammatory hyperpigmentation: typically follows a preceding inflammatory skin disorder or injury, with macular hyperpigmentation whose shape and distribution correlate with the antecedent…
- Diagnosis
Clinical pearl. A symmetrical eruption of irregular hyperpigmented patches on the forehead, cheeks, and chin without any preceding inflammatory trigger points to melasma; a shape and distribution…
- Management
First step, strict sun protection: apply broad-spectrum sunscreen and use sun-protective measures (clothing, hats) as the essential foundation of therapy; the most essential element of management is…
- Complications
Persistent or recurrent pigmentation: melasma can persist or recur with UV light exposure even after apparent resolution.
- Prognosis
Slow, variable resolution: it may take months to years for pigmentation to normalize.
- Prevention
Daily broad-spectrum sunscreen: apply broad-spectrum sunscreen with an SPF of at least 30 to affected and at-risk areas daily, reapplying every 2 hours during sun exposure.
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