Erythrasma is a superficial bacterial infection that commonly affects the skin between the toes, in the groin and in the axillae.

What causes it?

It is caused by the bacterium Corynebacterium minutissimum. It occurs in healthy individuals but is more common in those with diabetes mellitus or who are immunocompromised. It may also be more common with warmer climates, excess sweating and poor hygiene.

What does it look like?

Erythrasma presents as well-defined pink to brown patches in the axillae, groin or web spaces between the toes. There may be fine scaling present and the rash may be slightly itchy but is often asymptomatic. Wood’s lamp examination is a helpful tool to confirm the diagnosis as the bacteria cause a coral-pink fluorescence. The differential includes other skin conditions affecting the skin folds including intertrigo, inverse psoriasis, tinea, and candida infections.

How is it treated?

Mild disease can be treated with topical therapies such as clindamycin, erythromycin, fusidic acid or mupirocin. Widespread or resistant disease can be treated with oral antibiotics such as doxycycline or erythromycin. Antibacterial soaps can be used to help prevent recurrence.