Ashy Dermatosis

Key Points
Benign skin condition which typically affects the extremities, face, and/or torso
Exact cause is unknown, but may be a variation of Lichen planus
Consists of oval or round patches of skin which are grey in color and have a slightly diffused border

Erythema dyschromicum perstans is a benign skin condition which typically appears on the extremities, face, and/or torso. The condition consists of oval or round patches of skin which are grey in color and have a slightly diffused border. Patches may also be irregular in shape.

The cause of Erythema dyschromicum perstans is unknown. It is thought that the condition may be a variation of Lichen planus, though other theories for its development exist, such as heredity, exposure to certain toxins or medications, viral infection, and helminthic infestation. The condition is more likely to appear in persons with darker skin, most commonly those of Indian or Latino descent, though it may affect anyone, and appear at any age. Women are more commonly affected than men.

Differential Diagnosis (Other conditions with similar appearance)

Addison Disease
Contact Dermatitis
Hemochromatosis
Leprosy
Lichen Planus

Diagnosis
Key Points
Diagnosis based on appearance of the affected area
Skin biopsy will be performed to confirm diagnosis and rule out other conditions

Erythema dyschromicum perstans is typically diagnosed based on the appearance of the affected area. A skin biopsy will be performed to confirm the diagnosis and to rule out similar appearing conditions.

Treatment
Condition does not respond well to treatment
May resolve spontaneously in some cases
Various treatments may be prescribed, with varying effectiveness.

Erythema dyschromicum perstans does not respond well to treatment, though in some cases the condition may resolve spontaneously. In most cases, the condition is persistent, sometimes for years. Various treatments are available which may improve the appearance of discoloration, including topical steroids, UV radiation therapy, laser therapies, and chemical Peels. Systemic treatments might include Dapsone, Hydroxychloroquine, or corticosteroids.