Erythrasma L08.10

by Baerensprung, 1862

Clinically asymptomatic (no itching), chronic, "pseudomyotic" dermatitis of the intertriginous, caused by a superficial infection with pigment-forming corynebacteria.

Corynebacterium minutissimum ( porphyrin-producing corynebacteria with red fluorescence in wood light). The pathogens can penetrate into a horny layer swollen by moisture, but without reaching vital epidermis parts.

Worldwide spread. Prevalence (Central Europe): In about 4-6% of the population. Common in tropical climate zones (20% of the population)

Infection with Corynebacterium minutissimum (see also overview under Corynebacteria). Predisposing factors:

• warm and humid environment
• excessive sweating or local hyperhidrosis
• Maceration
• Obesity
• diabetes mellitus
• Immunosuppression e.g. in HIV infection.

m:f=1:1; 30-50 years (average: 44.6 years)

Mainly intertriginous areas: axillae (70-80%), scrotum, inguinal region, large labia, inner thigh, submammary.

Initially, preferably in the warm season, individual, 5.0-10.0 cm large, yellow-brown to reddish-brown, sharply defined, symptomless spots form, which confluent with increasing disease duration. Later flat plaques with fine scaling appear. Lesional itching can occur during longer periods of time and is intensified by sweating.

Frequently accompanying bromhidrosis.

Clinical picture

Wood light examination (320-400nm): coral red fluorescence of the infested areas.

Notice! Acid soaps, milieu sanitation. In stubborn cases, shave the affected areas. No fatty ointments. The patient should be informed that the hyperpigmentation may persist for several weeks after the pathogens have been removed!

Due to the progressive development of resistance (also with topical antibiotics), creams containing azole or ciclopirox should be preferred (e.g. bifonazole cream, ciclopirox cream). The application is usually carried out daily for one week, then if necessary 1x/week as prophylaxis.

Also important: Sanitation of the local millieu, thorough daily skin cleansing with water and (acid) syndets. If necessary, therapy control in the Wood light.

Favorable, frequent recurrences. Residual pigmentation often remains.

The clinical combination of Trichobacteriosis axillaris with Keratoma sulcatum and Erythrasma is not very rare.

Detection method Wood light: Dark red fluorescence, pathogen detection by tearing off with Sellotape.

1. Badri T et al (2014) Erythrasma: study of 16 cases. Tunis Med 92:245-248
2. Bandera A et al (2000) A case of costochondral abscess due to Corynebacterium minutissimum in an HIV-infected patient. J Infect 41: 103-105
3. Blaise G et al (2008) Corynebacterium-associated skin infections. Int J Dermatol 47:884-890.
4. Granok AB et al (2002) Corynebacterium minutissimum bacteremia in an immunocompetent host with cellulitis. Clin Infect Dis 35: e40-2
5. Holdiness MR (2003) Erythrasma and common bacterial skin infections. Am Fam Physician 67: 254
6. Nenoff P et al (2012) Bifonazole - in vitro efficacy against Corynebacterium minutissimum - an update on the diagnosis and treatment of erythrasma. Act Dermatol ; 38: 316-322
7. Polat M et al.(2015) The prevalence of interdigital erythrasma: a prospective study from an outpatient clinic in Turkey. J Am Podiatr Med Assoc 105:121-124
8. Rho NK et al (2008) A corynebacterial triad: prevalence of erythrasma and trichomycosis axillaris in soldiers with pitted keratolysis. J Am Acad Dermatol 58 (2 Suppl):S57-558