Acanthosis nigricans

Synonym(s)

None

Definition

Hyperpigmented, velvety thickening of the skin; most commonly on the neck, in the axillae, and in the groin

Pathogenesis

Caused by factors that stimulate epidermal keratinocyte and dermal fibroblast proliferation, such as insulin or an insulin-like growth factor

Clinical manifestation

Symmetrical, hyperpigmented, velvety plaques, which most commonly appear in the intertriginous areas; skin tags in the vicinity of the plaques

Differential diagnosis

Becker nevus; confluent and reticulated papillomatosis of Gougerot and Carteaud; Dowling-Degos disease; seborrheic keratosis; ichthyosis hystrix; linear epidermal nevus; parapsoriasis en plaque; pemphigus vegetans; hemochromatosis; Addison's disease; pellagra

Therapy

Correction of underlying disease process; weight reduction in obese patients; tretinoin 0.025% cream; adapalene 0.1% gel; calcipotriene; dietary fish oils; dermabrasion