Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Agents of Chromoblastomycosis
Chromoblastomycosis (chromomycosis) is a chronic, localized fungal infection of the skin and subcutaneous tissue that produces raised scaly lesions, usually of the lower extremities. The lesions of chromoblastomycosis are frequently warty or cauliflower-like in appearance, with pathognomonic muriform cells (also called “copper penny” or sclerotic bodies) found at histologic examination. This disease of tropical and subtropical distribution is produced by inoculation of the infecting fungi in association with minor trauma. Alexandrino Pedroso, for whom the major etiologic agent is named, first noted the disease in 1911, although the first publication to describe what was likely chromoblastomycosis appeared in 1914, authored by Max Rudolph. The first reports to include identification of the fungal cause of this disease were published 1 year later by Medlar and Lane, who described a patient with disease acquired not in the tropics but in the United States.
Etiologic Agents
Infection is caused by one of several dark-walled (dematiaceous) fungi found in the soil and in association with cacti, thorny plants, and other live or decaying vegetation. Fonsecaea pedrosoi is the most common cause of chromoblastomycosis. Other Fonsecaea species ( F. monophora and F. nubica ) and Cladophialophora carrionii are also common etiologic agents. Phialophora verrucosa and Rhinocladiella aquaspersa are less commonly reported. In the largest reports from Brazil, Mexico, Sri Lanka, India, and Japan, F. pedrosoi has been responsible for 66% to 96% of all infections. With the more recent recognition of F. monophora and F. nubica as new species, identification of these organisms as the cause of both new cases and old cases (with reidentification of isolates previously identified as F. pedrosoi ) of chromoblastomycosis continues to increase. Fonsecaea compacta is currently believed to be a variant of F. pedrosoi and not a distinct species. Rare or isolated reports of disease caused by Botryomyces caespitosus, Chaetomium funicola, Cladophialophora arxii, Cladophialophora boppii, Cyphellophora ludoviensis, Exophiala (Wangiella) dermatitidis, Exophiala jeanselmei, Exophiala spinifera, Fonsecaea pugnacius , Phaeosclera dermatioides, Rhinocladiella phaeophora, Rhinocladiella similis, Rhinocladiella tropicalis, and Rhytidhysteron species have been published.
Epidemiology
Chromoblastomycosis has been described to occur throughout the world, although most cases arise in tropical and subtropical regions, especially those with high annual rainfall. Large numbers of cases have been described from Madagascar, Brazil, Mexico, Venezuela, and Costa Rica. Disease is more prevalent in males (4 : 1 ratio), in those aged 40 to 69, in association with outdoor activities such as farming and woodcutting, and in the absence of footwear. In Madagascar, a unique epidemiology has been described in what is probably the largest focus of endemic disease. Madagascar has two distinct foci of infection, with disease secondary to F. pedrosoi occurring in the humid, rainy, northern evergreen forest region and disease secondary to C. carrionii found in the arid southern desert region. In a study of 1343 cases of disease over 40 years in that country, the prevalence of 1 case per 1920 inhabitants in the southern desert region has been described, with an incredible 1 in 910 prevalence in a single district of that region.
You're Reading a Preview
Become a Clinical Tree membership for Full access and enjoy Unlimited articles
If you are a member. Log in here