ERYTHRASMA

DERMATOLOGY LECTURE NOTES

DEBABRATA BANDYOPADHYAY
PROFESSOR & HEAD, DEPT. OF DERMATOLOGY,
R. G. KAR MEDICAL COLLEGE, CALCUTTA, INDIA

Erythrasma is a mild, superficial infection of the skin caused by a group of closely related bacteria designated as Corynebacterium minutissimum. Erythrasma runs a chronic course and is rarely produces any symptom.
 

ETIOLOGY

Erythrasma is caused by a group of aerobic Gram-positive, coryneform bacteria usually known as Corynebacterium minutissimum. The bacteria may be a part of normal skin flora in sites like toe clefts. Favorable factors like warmth and moisture may help pathogenicity of the organism. Coproporphyrin III, produced by the organism is responsible for the coral red fluorescence under Wood’s lamp examination.
 

CLINICAL FEATURES

• Erythrasma can occur at any age, but it is more frequent in adults.

• Sharply marginated, reddish patches with irregular borders, which later become brownish with superficial scaling, are characteristic.

• Erythrasma usually do not produce any symptoms but itching and irritation may occur in hot and humid tropical climates.

• Most common site of affection is toe-clefts, but in this location it is rarely clinically detected.

• Typical lesions are more common on major body folds like groin, axillae, natal cleft, and inframammary regions. Rarely, penis, scrotum, and perianal region may be affected.

• The lesions demonstrate a characteristic coral red fluorescence under Wood’s lamp examination.

DIFFERENTIAL DIAGNOSIS

• Tinea cruris

• Candidiasis

• Pityriasis versicolor
   

DIAGNOSIS

Erythrasma is diagnosed clinically by the typical asymptomatic, non-inflammatory, reddish or brown patches over body folds. Wood’s lamp examination is contributory. KOH mount examination may be necessary to exclude superficial mycoses.
 

COURSE AND PROGNOSIS

TREATMENT

• Topical azole antifungals, like miconazole, clotrimazole, or ketoconazole continued for a few weeks are curative. Topical antibacterials like fusidic acid are also effective.

• Oral tetracyclines or erythromycin are alternative modes of therapy.

• Relapse may be a problem. Keeping the areas clean and dry and regular use of antibacterials soaps may prevent this.