Erythrasma is a long-term skin infection caused by a specific bacteria. It commonly occurs in skin folds.

Erythrasma is caused by the bacteria Corynebacterium minutissimum.

Erythrasma is more common in warm climates. You are more likely to develop this condition if you are overweight, older, or have diabetes.

The main symptoms are reddish-brown slightly scaly patches with sharp borders. They may itch slightly. The patches occur in moist areas such as the groin, armpit, and skin folds.

The patches often look similar to fungal infections, such as ringworm.

Your health care provider will check your skin and ask about the symptoms.

These tests can help diagnose erythrasma:

• Lab tests of scrapings from the skin patch
• Examination under a special lamp called a Wood lamp
• A skin biopsy

Your provider may suggest the following:

• Gentle scrubbing of the skin patches with antibacterial soap
• Antibiotic medicine applied to the skin
• Antibiotics taken by mouth
• Laser treatment

The condition should go away after treatment. 

Contact your provider if you have symptoms of erythrasma.

You may be able to reduce the risk of erythrasma if you:

• Bathe or shower often
• Keep your skin dry
• Wear clean clothes that absorb moisture
• Avoid very hot or damp conditions
• Maintain a healthy body weight

Barkham MC, Khong B. Erythrasma. In: Lebwohl MG, Heymann WR, Coulson IH, Murrell DF, eds. Treatment of Skin Disease. 6th ed. Philadelphia, PA: Elsevier Limited; 2022:chap 77.

Dinulos JGH. Superficial fungal infections. In: Dinulos JGH, ed. Habif's Clinical Dermatology. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 13.