Seborrheic keratoses

Seborrheic keratosis consists of benign, verrucous (wart-like), often pigmented, greasy lesions consisting of proliferating epidermal cells which usually occur after the third decade.

A common occurrence among black people is the appearance of many small lesions on the face, known as dermatosis papulosa nigra.

Leser-Trelat sign, the explosive onset of multiple pruritic seborrheic keratoses, often with an inflammatory base, can be an ominous sign of internal malignancy, especially stomach carcinoma.