Chomoblastomycosis

Synonyms

Medlar bodies; muriform bodies; copper pennies.

Epidemiology

Affecting mostly adult male agricultural workers in the rural tropical and subtropical areas of the world.

Definition

Chronic granulomatous infection of the skin and subcutaneous tissue caused by several different brown pigment-producing (dematiaceous) fungi.

Aetiology & Pathogenesis

A large number of dematiaceous, i.e.brown pigment producing, fungi can cause the disease, the most common of which are Cladosporium carrionii, Phialophora verrucosa, and Fonsecaea pedrosoi, present in wood an soil.

Signs & Symptoms

Localized, slowly growing and peripherally extending, warty cauliflower-like plaques, which may ulcerate. Sclerotic bodies are extruded tranaepidermally, appearing as black dots. Large hyperkeratotic and ulcerating masses may form. The lesion is usually painless. Sometimes lymphatic spread due to scratching result in the sporotrichoid pattern. Hematogenous dissemination with brain abscesses is very rare.

Localisation

Areas exposed to trauma.

Classification

None.

Laboratory & other workups

Microbiology; 10% KOH.

Dermatopathology

Marked pseudoepitheliomatous hyperplasia of the epidermis. Transepidermal elimination of fungal cells, which are in the stratum corneum. Foreign-body granuloma with isolated microabscesses. In the dermis, a granuloma composed of epithelioid cells and Langhans giant cells is visible. The golden-brown fungal elements are visible as thick-walled, single, or multicelled clusters, forming sclerotic or muriform bodies.

Course

Chronic, but curable. The prognosis depends on the size of the lesions and the immune status of the patient. Long-standing cases can spread over joints and lead to lymphatic involvement and elephantiasis. Disseminated disease, with the involvement of the central nervous system, has the worst prognosis.

Complications

Ulceration, secondary bacterial infection, lymphedema resulting in elephantiasis. Malignant transformation to squamous cell carcinoma is rare.

Diagnosis

Clinical feature, histologic and microbial findings.

Differential diagnosis

Other verrucous lesions: tuberculosis verrucosa cutis, verruca vulgaris, blastomycosis, Yaws, verrucous hemangioma, hypertrophic lichen planus, lupus vulgaris. Sporotrichosis in sporotrichoid type. Psoriasis.

Prevention & Therapy

Prevention of trauma.

Best results are achievable in small lesions with surgery, cryotherapy or electrodessiccation in combination with antifungal therapy: itraconazole 200 to 400 mg/day or terbinafine, 250 to 500 mg/day given for a period varying from 6 months to a year or more. Flucytosine alone or combined with amphotericin and oral supersaturated potassium iodide solution are additional options.

Special

Best management is by an interprofessional team, including an infectious disease consultant, surgeon, emergency department physician, wound care nurse, and an internist.

10.2.1 Chomoblastomycosis