Acanthosis Nigricans: Causes, Symptoms and Medical Significance

Introduction: Acanthosis nigricans is a skin condition characterised by darkened, thickened and velvety patches, commonly appearing on the neck, armpits and groin.

Key pointers

  • Nature: A dermatological condition rather than a single infectious disease.

  • Appearance: Hyperpigmented, thickened and velvety skin.

  • Common locations: Neck folds, axillae and groin.

  • Major association: Insulin resistance.

  • Related conditions: Obesity, type 2 diabetes and metabolic syndrome.

  • Hormonal associations: May occur with certain endocrine disorders.

  • Medication-related cases: Some medicines can contribute to its development.

  • Malignancy association: Rarely, rapidly developing and extensive acanthosis nigricans can be associated with an underlying malignancy, particularly certain gastrointestinal cancers.

  • Diagnosis: Clinical assessment, with investigation of possible underlying causes when indicated.

  • Management: Focuses on identifying and treating the underlying cause; skin-directed treatments may help in selected cases.

UPSC focus: Acanthosis nigricans is an important clinical clue to possible insulin resistance, but its presence alone does not establish a diagnosis of diabetes.