Cromoblastomicosis: primer caso alóctono tratado en Chile / Chromoblastomycosis: first allochthonous case treated in Chile

Resumen La cromoblastomicosis es una infección fúngica de la piel y del tejido subcutáneo, de evolución crónica, causada por hongos dematiáceos que se caracterizan por presentar melanina en su pared celular. La enfermedad se presenta en todo el mundo, principalmente en regiones tropicales y subtropicales. En Chile, solo hay un reporte de caso humano hace más de 30 años. Se presenta el caso de un varón de 46 años, haitiano, residente en Chile, con placas verrucosas en la zona tibial anterior de un año de evolución. El diagnóstico de cromoblastomicosis se confirmó al observar células muriformes en la histopatología y colonias dematiáceas en el cultivo micológico; además, en la miscroscopía directa se observaron conidias compatibles con Fonsecaea spp. Luego de seis meses de tratamiento con antimicóticos sistémicos y crioterapia, se logró la remisión completa de las lesiones.

Abstract Chromoblastomycosis is a fungal infection of the skin and subcutaneous tissue, of chronic evolution, caused by dematiaceous fungi. The disease occurs worldwide, mainly in tropical and subtropical regions, but in regions like Chile there is only one report of a human case more than 30 years ago. We present the case of a 46-year-old Haitian man, resident in Chile, with verrucous plaques in the right anterior tibial area of one year of evolution. The diagnosis of chromoblastomycosis was confirmed when muriform cells and dematiaceous colonies were observed in the histopathological analysis and the direct microscopy, respectively. After six months of treatment with systemic antimycotics and cryotherapy, complete remission of the lesions was achieved.

Concurrent mycetoma and chromomycosis.

Chromoblastomycosis and Madura foot are chronic localised mycotic infection of the skin and subcutaneous tissue that follows the implantation of the fungi through minor trauma, mainly found in persons working outdoors on bare foot. In cases where both Madura and chromoblastomycosis are present, the treatment becomes difficult with low cure rates and frequent relapses. Here, we present such a very rare case of a 38-year-old cattle farmer who presented with verrucose nodules, tumefaction and multiple discharging nodules on the left lower 1/3 rd leg and foot since last 9 years. Direct KOH mount of the verrucose tissue showed Fonsecaea pedrosoi sclerotic muriform bodies and a biopsy of one granule discharging nodule demonstrated fungal mycetoma. He was put on tab. Itraconazole 200 mg o.d. and cotrimoxazole bid for 6 months with very little improvement. The rarity of this combination is most probably due to different geographical distribution.

'Unstained' and 'de stained' sections in the diagnosis of chromoblastomycosis: A clinico-pathological study.

Background: Diagnosis of chromoblastomycosis is frequently missed for many reasons: (1) rarity of the lesion (2) requirement of careful search for diagnostic 'sclerotic' bodies which are often sparse in clinical material such as tissue and exudates (3) often they elicit tissue reactions such as verrucous lesion and micro abscesses, misleading the diagnosis (4) lack of 'clinical suspicion'. Aims: (1) To compare the feasibility of 'unstained', 'stained' and 'de stained' sections in identification of the diagnostic ' sclerotic' bodies (2) To study histopathological features of chromoblastomycosis, and (3) To highlight the importance of clinical suspicion in the diagnosis of chromoblastomycosis. Design : This is a retrospective study conducted on six clinically unsuspected, histopathologically diagnosed cases of chromoblastomycosis. Results: Most common clinical presentation was verrucous lesion over extremities affecting adult men engaged in outdoor works. Sclerotic bodies and their characteristic features were easily identified in both 'unstained' and 'de stained' sections. Special stains such as Fontana Masson and Gomori's methenamine silver nitrate are useful for demonstrating hyphal forms in keratinized layers and for illustration purposes. Conclusion: Both 'unstained' and 'de stained' sections can be used for rapid screening of sclerotic bodies. 'De stained' sections can be used as a suitable substitute for special stains for confirmation and for retrospective review of all verrucous lesions to diagnose the missed lesion. Clinical suspicion is very important in the diagnosis of chromoblastomycosis as it helps pathologist to screen for diagnostic sclerotic bodies.