Acanthosis nigricans: Pathogenesis, differential diagnosis, and evidence-based management

Acanthosis nigricans (AN) is a common dermatologic condition characterized by hyperpigmented, velvety plaques that most frequently affect intertriginous areas. Although often associated with insulin resistance and obesity, AN may also serve as a cutaneous marker of underlying endocrinologic disorders, medication effects, genetic syndromes, or internal malignancy. Recognition of AN provides an important opportunity for early identification of systemic disease and implementation of targeted management strategies. This review summarizes the pathogenesis and etiologic subtypes of AN, highlights key clinical features and differential diagnoses, and outlines an evidence-based diagnostic approach. Management strategies are discussed with emphasis on lifestyle modification, pharmacologic therapies, topical treatments, procedural interventions, and the strength of supporting evidence. Practical considerations relevant to physician assistants are emphasized throughout, including interdisciplinary care and patient education. Early recognition and appropriate management of AN can improve both dermatologic outcomes and overall patient health.