Chromoblastomycosis

Key Points
Chronic fungal infection
Caused by various fungi which enter the skin through minor injuries
Consists of lesions affecting the skin and subcutaneous tissue of the limbs, which are raised and crusted

Chromoblastomycosis is a chronic fungal infection. Infection occurs when causal organisms enter the skin through the sites of minor injuries. The infection initially consists of a small red or grey papule, which grows very slowly, and eventually becomes warty or shifts into a plaque. The affected area will be dry, and often partially heals, with scar tissue left in the center of the lesion. Over time, new, or satellite, lesions will form in relation to the first lesion. New lesions may also form when the first occurrence is scratched and the infection transferred to another area. Lesions are painless but very itchy. In some cases, the affected limb may experience general enlargement, or Elephantiasis. Rarely, Squamous Cell Carcinoma may result from longstanding periods of infection.

Chromoblastomycosis is caused by microorganisms entering the body through small fissures, injuries, or other breaks in the skin. The organisms most commonly responsible for the condition include Phialophora Verrucosa, Fonsecaea Pedrosi, Fonsecaea Compacta, Cladosporium Carrionii, and Rhinocladiella.

Differential Diagnosis (Other conditions with similar appearance)

Leishmaniasis
Sporotrichosis
Squamous Cell Carcinoma
Bacterial infection
Psoriasis

Diagnosis
Key Points
Initial diagnosis suggested by skin appearance
Biopsy, skin cultures, and microscopy confirm diagnosis

Chromoblastomycosis's initial diagnosis is suggested by the appearance of lesions. Diagnosis can then be confirmed by several methods, including biopsy, skin cultures, and microscopic examination.

Treatment
In rare cases, may resolve spontaneously
Difficult to treat
Goal of treatment is to eliminate the causative fungus
*Lesions may be excised or destroyed by health care professionals

Chromoblastomycosis is notoriously difficult to treat, and treatment may be long-term, and involve combinations of drug therapy and surgical or destructive techniques. Medications used to combat the condition include Itraconazole, Flucytosine, and Thiobendazole. Itraconazole is the most commonly used of these. In some cases, health care professionals may recommend a multi-drug therapy in conjunction with cryosurgery. Heat therapy, the application of heat to the affected area, has been shown in some cases to be effective, but the therapy may take up to 6 months or more to completely eliminate the condition. It is thought to be effective because the increase in heat in the affected area makes it more difficult for the fungus to live.