A skin condition characterized by increased pigmentation (darkening of the skin) and hyperkeratosis (thickening of the skin). It occurs most commonly in the flexural skin areas (behind knee, front of elbow, neck, etc.). The disorder is related to insulinmetabolism and appears in diseases which affect insulin metabolism including obesity . In adults the condition may be associated with malignant tumors.

This can affect person of any age, however it is common in adults and people with dark colored skin. Both males and females are equally affected

People who are at higher risk include:

• Obese or overweight people
• Any endocrine abnormality
• Person on certain medicines like corticosteroids and oral contraceptive
• Any internal malignancy
• Kidney disease