By Gary M. White, MD


Erythrasma is a superficial infection of the flexures of the skin caused by the bacteria Corynebacterium minutissimum. Corynebacterium afermentans has also been reported [AD 1996;132;716]. The typical clinical finding is a red-brown non-scaly patch in a moist, intertriginous area, e.g. the groin. Wood's lamp shows a characteristic coral-pink fluorescence.

Some patients may be affected by the so called corynebacterial triad:

Differential Diagnosis

Tinea cruris is KOH positive. Erythrasma fluoresces a coral pink. If not either of those, it is probably intertrigo.


Erythromycin topically or orally is effective. Topical clindamycin is an alternative. A single gram dose of clarithromycin has been reported effective [AD 1998;134;671]. Some studies support the effectiveness of antimicrobial soaps against erythrasma and these can be recommended to prevent recurrences. Mupirocin 2% ointment bid is effective.

Additional Pictures

Erythrasma of the axilla with positive Wood's light fluorescence (coral pink).
Erythrasma Positive Fluorescence in Erythrasma

Erythrasma of the groin with positive Wood's light fluorescence (coral pink).
Erythrasma erythrasma with positive Wood's light fluorescence



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