Abstract
Diagnosis: Chromoblastomycosis. Microscopic and laboratory findings and clinical course The histopathologic findings included hyperkeratosis, pseudoepitheliomatous hyperplasia, and a granulomatous inflammatory reaction with microabscess formation. Spherical, brown sclerotic bodies were present in the inflammatory infiltrate (Figure 3). A silver stain confirmed the presence of fungal organisms. Tissue culture yielded Fonsecaea pedrosoi. Our patient is currently being treated with systemic terbinafine therapy combined with monthly cryotherapy. Some areas of regression have been noted. View LargeDownload Figure 3. Discussion Chromoblastomycosis is a subcutaneous mycosis that is acquired by cutaneous inoculation with dematiaceous fungi.1Fonsecaea pedrosoi, Fonsecaea compactum, Cladosporium carrionii, Rhinocladiella aquaspersa, and Phialophora verrucosa are the 5 most commonly reported organisms causing chromoblastomycosis.2,3Fonsecaea pedrosi is the most frequent isolate.4 These saprophytic fungi are found in decaying vegetation and soil and can cause human infection by transcutaneous implantation.1 Most lesions present on the lower extremities of persons working outdoors in agricultural occupations.2 Males are affected more often than females. Typically, patients acquire the infection between the ages of 30 and 50 years.4 Chromoblastomycosis begins as a small, solitary, crusted or scaly, pink papule.3,4 The initial papule may develop into a nodule or may expand to form a hyperkeratotic or verrucous plaque. Nodular, verrucous, plaquelike, tumorous, and cicatricial lesions have been described by Carrion.5 “Black dots” may be present within the crust of the lesions and represent transepithelial elimination of fungal organisms and hemorrhage.6 Rarely, chromoblastomycosis may disseminate by autoinoculation, lymphatic spread, or hematogenous routes.3 Histologic examination demonstrates a hyperkeratotic stratum corneum with pseudoepitheliomatous epidermal hyperplasia.2 The dermis often shows a granulomatous infiltrate, abscess formation, and varying degrees of suppuration and fibrosis.4 Spherical, brown, 6- to 12-μm bodies known as sclerotic bodies, Medlar bodies, or “copper pennies” are present either extracellularly or within the cytoplasm of giant cells.2 Potassium hydroxide examination of scale from areas of black dot formation may allow microscopic visualization of sclerotic bodies singly or in clumps.6 Surgery, cryotherapy, thermotherapy, and systemic antifungal therapy have all been used to treat chromoblastomycosis. Surgical removal is best reserved for small lesions.2,7 Daily, direct application of heat (42°-46°C) over a period of 2 to 12 months has resulted in successful treatment of small lesions.7,8 Systemic antifungal agents used in the treatment of chromoblastomycosis include itraconazole, fluconazole, amphotericin B, terbinafine, and flucytosine.7,9,10 Frequently, the clinical course is chronic and slowly progressive, with little tendency to resolve, even with appropriate therapy. References 1. Rubin HABruce SRosen TMcBride ME Evidence for percutaneous inoculation as the mode of transmission for chromoblastomycosis J Am Acad Dermatol 1991;25951- 954PubMedGoogle ScholarCrossref 2. Elgart GW Chromoblastomycosis Dermatol Clin 1996;1477- 83PubMedGoogle ScholarCrossref 3. Bayles MAH Chromomycosis Curr Top Med Mycol 1995;6221- 243PubMedGoogle Scholar 4. McGinnis MR Chromoblastomycosis and phaeohyphomycosis: new concepts, diagnosis, and mycology J Am Acad Dermatol 1983;81- 16PubMedGoogle ScholarCrossref 5. Carrion AL Chromoblastomycosis Ann N Y Acad Sci 1950;501255- 1282PubMedGoogle ScholarCrossref 6. Zaias NRebell G A simple and accurate diagnostic method in chromoblastomycosis Arch Dermatol 1973;108545- 546PubMedGoogle ScholarCrossref 7. Restrepo A Treatment of tropical mycoses J Am Acad Dermatol 1994;31S91- S102PubMedGoogle ScholarCrossref 8. Tagami HGinoza MImaizumi SUrano-Suehisa S Successful treatment of chromoblastomycosis with topical heat therapy J Am Acad Dermatol 1984;10615- 619Google ScholarCrossref 9. Bonifaz AMartinez-Soto ECarrasco-Gerard EPeniche J Treatment of chromoblastomycosis with itraconazole, cryosurgery, and a combination of both Int J Dermatol 1997;36542- 547PubMedGoogle ScholarCrossref 10. Esterre PInzan CKRamarcel ER et al. Treatment of chromomycosis with terbinafine: preliminary results of an open pilot study Br J Dermatol 1996;134(suppl 46)33- 36PubMedGoogle ScholarCrossref
Journal
Archives of Dermatology
– American Medical Association
Published: Nov 1, 2005
Keywords: chromoblastomycosis,forearm
