Chromoblastomycosis

Chromoblastomycosis 2

Chromoblastomycosis is a chronic fungal infection of the skin and subcutaneous tissue, characterized by the formation of nodular and verrucous lesions. The disease is caused by the traumatic implantation of dematiaceous (darkly pigmented) fungi into the skin. These fungi belong to several genera, including Fonsecaea, Cladophialophora, and Phialophora. Chromoblastomycosis is most commonly reported in tropical and subtropical regions, affecting individuals involved in agricultural activities, due to the higher risk of trauma with vegetative materials.

Etiology and Pathogenesis

Chromoblastomycosis is caused by the inoculation of dematiaceous fungi into the skin. These fungi are found in soil and on decomposing plant material. The infection begins when the fungal spores penetrate the skin through a minor cut or abrasion. Once inside the skin, the fungus proliferates and forms characteristic sclerotic bodies or muriform cells, which are large, thick-walled, brown cells that can be observed in tissue samples.

Clinical Manifestations

The clinical presentation of chromoblastomycosis can vary but typically starts as a small papule at the site of inoculation, which gradually enlarges to form nodules, plaques, or verrucous lesions. These lesions can become scaly, crusted, and may ulcerate. The disease progresses slowly over years and can lead to significant disfigurement and disability, especially when lesions are located on the limbs. Lymphatic spread is common, leading to lymphedema and elephantiasis.

Diagnosis

Diagnosis of chromoblastomycosis is primarily based on clinical findings, histopathological examination of biopsy specimens, and culture of the fungus. Histopathology reveals the presence of sclerotic bodies within the tissue. Cultures allow for the identification of the specific fungal species involved.

Treatment

Treatment of chromoblastomycosis can be challenging and often requires a combination of surgical and medical approaches. Antifungal therapy with drugs such as itraconazole or terbinafine is commonly used, but treatment duration can be prolonged, sometimes lasting years. Severe or refractory cases may require surgical excision of the lesions. Photodynamic therapy has also been explored as a treatment option.

Epidemiology

Chromoblastomycosis has a worldwide distribution but is most prevalent in tropical and subtropical regions, including parts of Africa, Central and South America, and Southeast Asia. The disease affects more men than women, likely due to occupational exposure, and is more common in adults.

Prevention

Preventive measures for chromoblastomycosis include wearing protective clothing and footwear to avoid skin trauma while engaging in outdoor activities, especially in areas where the causative fungi are endemic.