Hypopigmentering

Hypopigmentering, also called hypopigmentation, refers to patches of skin that are lighter than the surrounding skin due to reduced melanin production or loss of pigment-producing cells. It differs from depigmentation, in which pigment is completely absent. Hypopigmentering can be focal or widespread and may affect hair in the affected area.

Common causes include post-inflammatory hypopigmentation after skin inflammation or injury (for example after acne, eczema, abrasions), pityriasis alba in children, and fungal infections such as tinea versicolor. Less frequently, genetic or congenital conditions with partial pigment loss can produce hypopigmented patches. Scarring, burns, chemical exposures, and certain medications can also contribute. Vitiligo typically leads to depigmentation rather than hypopigmentation.

Diagnosis is usually clinical, based on the appearance of the patches and their distribution. A Wood lamp examination can aid assessment, as some causes show characteristic fluorescence; fungal infections may be suggested by microscopy or culture. In uncertain cases, skin biopsy or laboratory tests to identify infection or inflammatory causes may be performed.

Treatment depends on the underlying cause. Many post-inflammatory patches gradually repigment over months; sun protection is advised to prevent uneven tanning. Fungal infections are treated with appropriate antifungal agents. Active inflammation may be managed with topical steroids or calcineurin inhibitors and moisturizers. In persistent or cosmetically distressing cases, dermatologists may consider procedures such as laser therapy or pigmentary camouflage, though results vary and some patches remain permanent.