A 30-year-old pregnant woman develops symmetric brown hyperpigmentation over the malar cheeks, forehead, and upper lip. The pigmentation is limited to sun-exposed areas and worsened during pregnancy. On Wood's lamp examination the pigmentation is accentuated. Which type of melasma does she have?

• A Dermal melasma
• B Mixed melasma
• C Indeterminate melasma
• D Epidermal melasma ✓

Explanation

Melasma is classified based on the depth of pigmentation assessed by Wood's lamp examination. Epidermal melasma shows accentuation (enhanced contrast) under Wood's lamp because the excess melanin is in the epidermis where Wood's lamp penetrates well. Dermal melasma does not show accentuation under Wood's lamp. Epidermal type responds better to topical depigmenting agents. The pregnancy-related form is called chloasma or mask of pregnancy, driven by elevated estrogen and progesterone stimulating melanocyte-stimulating hormone.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.