Acanthosis nigricans is a skin condition characterized by hyperpigmentation and thickening of the skin, occurring mainly in the armpits, groin and neck. These velvety plaques are distributed symmetrically on the neck, arm pits, thighs, behind the knee and elbow joints, umbilicus and perianal areas. Involvement of the dorsum of the hands and fingers can occur in patients with advanced acanthosis nigricans.
- Hereditary - This is genetically transmitted. Manifests at birth or early childhood.
- Endocrine disorders - Hypothyroidism, Insulin resistant Diabetes mellitus, Acromegaly, Cushings sydrome are the conditions where acanthosis nigricans is seen. Triad of hyper androgenism, insulin resistance, acanthosis nigricans in women is called HAIR-AN syndrome.
- Obesity - Most common type and seen in obese people. The skin changes are reversible on weight reduction.
- Drug or medicine induced - Corticosteroids, stilbestrol, oral contraceptives are some medications which cause acanthosis nigricans.
- Auto immune diseases - Due to development of antibodies against insulin receptors in certain autoimmune conditions like Systemic Lupus Erythematosus.
- Malignancy - In few elderly persons acanthosis nigricans is seen with an internal carcinoma particularly stomach.
Visit your dermatologist if you have the above mentioned symptoms of Acanthosis nigricans. Your doctor will assess the condition, try to find out the underlying cause and treat accordingly.