Acanthosis nigricans
Acanthosis nigricans
Acanthosis nigricans causes dark velvety skin and may signal insulin resistance, prediabetes, diabetes or PCOS.
What is acanthosis nigricans?
Acanthosis nigricans causes dark, thickened, velvety skin, commonly on the neck, armpits or groin. It is not dirt and cannot be scrubbed away. It often accompanies insulin resistance, but it is a physical finding—not a diagnosis by itself.
Causes and associations
Insulin resistance
Common with obesity, prediabetes, type 2 diabetes and PCOS.
Medicines
High-dose niacin, systemic steroids, hormonal medicines and some other drugs may contribute.
Genetic or endocrine conditions
Rare inherited syndromes and endocrine disorders may present with it.
Rare malignancy association
Sudden, extensive, rapidly progressive disease—especially in a lean older adult—requires prompt evaluation.
Clinical evaluation
- History of onset, progression and symptoms
- Examination of distribution and related skin findings
- Weight, waist, blood pressure and medication review
- A1c or fasting glucose when indicated
- PCOS or endocrine evaluation based on symptoms
- Dermatology assessment or biopsy when the appearance is atypical
Treatment focuses on the cause
Improving insulin resistance and weight can fade lesions over time, but change is not immediate or guaranteed. Dermatologic treatments may improve texture or appearance. Bleaching or aggressive scrubbing can irritate skin without treating the underlying process.
How W8MD can help
W8MD can assess metabolic risk, coordinate glucose testing, review PCOS and medication factors, screen for sleep apnea and offer evidence-based weight treatment when appropriate. Atypical or rapidly progressive findings are referred promptly.
Frequently asked questions
Does acanthosis mean I have diabetes?
No, but it can signal insulin resistance and supports appropriate testing.
Is it contagious?
No.
Will GLP-1 medication remove it?
Metabolic and weight improvement may help indirectly, but it is not an approved skin treatment.
Authoritative sources
Request a metabolic-risk evaluation
W8MD Weight Loss, Sleep & MedSpa provides physician-supervised care in Brooklyn, New York and Northeast Philadelphia. Telehealth may be available for eligible patients based on location and applicable requirements.
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