Nummular eczema is an allergy-related disorder in which itchy, coin-shaped spots or patches appear on the skin.

The cause of nummular eczema is unknown, but there usually is a personal or family history of asthma, allergies, atopic dermatitis, or similar disorder. It is relatively uncommon, and most often occurs in elderly men.

Several things may make the condition worse, including

• Dry skin
• Environmental irritants
• Stress
• Temperature changes

• Coin-shaped skin lesions
  • On the arms and legs
  • May spread to middle of body
  • Ooze and become crusty
• Itching
• Scaly or raw skin
• Skin redness or inflammation

Your doctor can usually diagnose this condition by looking at your skin and asking you about your family's medical history.

A skin biopsy may be needed to rule out other similar conditions.

You should avoid triggers, such as wool, lanolin, and certain foods, that can make symptoms worse. Experts do not recommend taking frequent baths - excess bathing and soaps can cause dry skin, which often makes the condition worse.

Your doctor may recommend soothing skin lotions, soaps, or moist bandages to soothe scaly, dry, or healing areas.

Persons with severe symptoms may be given skin ointments or creams that contain tar, corticosteroids, skin softeners, or moisturizers. In rare, severe cases, the doctor may prescribe more powerful corticosteroids to be taken by mouth or injection.

Nummular eczema is a long-term (chronic) condition. Medical treatment and avoiding irritants can help reduce symptoms.

A secondary infection of the skin may develop.

Call your health care provider for an appointment with if you have symptoms of this condition.

You should also call for an appointment with your health care provider if:

• Symptoms continue despite treatment
• You have signs infection (such as fever, redness, or pain)

There is no known way to prevent the disorder. You should avoid things that are known to make your symptoms worse.

Habif TP. Clinical Dermatology. 4th ed. St. Louis, Mo: Mosby; 2004.

Noble J. Textbook of Primary Care Medicine. 3rd ed. St. Louis, Mo: Mosby; 2001.