Diagnosis: Acanthosis nigricans
Description: Hyperpigmented plaques
Morphology: Hyperpigmentation
Site: Perioral
Sex: F
Age: 27
Type: Clinical
Submitted By: Nameer Al-Sudany
Differential DiagnosisHistory: Acanthosis nigricans is an uncommon condition. The flexures and neck typically show epidermal thickening and pigmentation and the skin is velvety or papillomatous. Warty lesions are seen around the mouth and on the palms and soles. This lady unfortunately mistakenly was diagnosed as melasma and as perioal frictional melanosis and recieved many topical preparations with no benefit. She presented with hyperpigmented velvety-like plaques around the mouth area bilaterally and both nasolabial folds for more than one year.