American Policing

Chromoblastomycosis

Chromoblastomycosis is a chronic fungal infection of the skin and the subcutaneous tissue caused by traumatic implantation of a specific group of dematiaceous or brown pigmented fungi (usually Fonsecaea pedrosoi, Phialophora verrucosa, Cladosporium carrionii, or Fonsecaea compacta) through the skin.

Chromoblastomycosis was first described in 1914 by Max Rudolph, a German physician living in Brazil. Rudolph was able to isolate a dark-colored fungus from patients; this fungus grew in culture as a dark gray-to-blackÐ'-colored furlike colony. Chromoblastomycosis is known to be ubiquitous; however prevalence is higher in bare footed populations living in tropical regions, such as Madagascar in Africa and Brazil in South America.

The infection usually results from a traumatic cutaneous injury that is often not remembered or realized by the patient. The sites most commonly affected are the lower extremities, especially the feet. The hands, the arms, and the buttocks are also frequently involved, and sporadic reports mention lesions on the ears, the face, and the breasts. The agents often gain entry into the human body by contact with wood splinters or thorns. The fungi most commonly reported as causing chromoblastomycosis are F pedrosoi, C carrionii, and P verrucosa. A small number of cases due to F compacta, R aquaspersa, and different species of Exophiala have also been reported. Over months to years a small red papule develops at the site of implantation, producing a warty nodule, which tends to be limited to the skin and the subcutaneous tissue. The central portion of the lesion may heal, producing a scar, or it may ulcerate. The disease tends to spread to neighboring healthy skin, forming plaques which may become ulcerated, or multiple nodules may grow and coalesce affecting a large area of a limb. See the photograph on the next page for an example. When nodular lesions predominate over the plaques, the disease assumes a typical cauliflower aspect. Blood vessel and/or lymphatic spread may occur. Secondary bacterial infection may occur, sometimes inducing lymphatic obstruction which causes elephantiasis. In 1999, Castro devised physician friendly index to stage chromoblastomycosis. The severity index is based on the extension of the diseased area, the number of lesions, the presence of complications (eg, lymphedema, ulceration, secondary infection), and the unresponsiveness to previous treatments. According to this scoring system, patients are classified as having mild (up to 3 points), moderate (4-6 points), or severe (7-10 points) disease.

Ð'* Scoring system for staging chromoblastomycosis:

o Area of lesions: Small lesions up to 25 cm2 are 1 point. Medium lesions larger than 25 cm2 and smaller than 100 cm2 are 2 points. Lesions larger than 100 cm2 are 3 points.

o Number of lesions: A single lesion is 1 point. One to 5 lesions is 2 points. More than 5 lesions or metastatic lesions is 3 points.

o Complications (1 point for each complication present): Lymphedema is 1 point. Ulceration is 1 point. Secondary infection is 1 point.

o Resistance to previous treatment or previous unsuccessful treatment is 1 point.

A 67-year-old man with limb infected chromoblastomycosis. A skin biopsy revealed a suppurative and granulomatous infiltrate with clusters of brown fungal organisms (muriform cells), a finding diagnostic of chromoblastomycosis (inset).

Superficial crusts mounted in 10% KOH contain brown pigmented, septate branching hyphae 2-5 Ð'µm in diameter. Pus and granulation tissue obtained