Chromoblastomycosis caused by Chaetomium funicola: a case report from Western Panama

Summary Little is known about opportunistic fungi causing skin lesions in tropical countries such as Panama. We report an 83‐year‐old man from Chiriquí, Western Panama, with crusted skin lesions covering tumorous masses resembling Bowen’s disease of the skin on the dorsum of his right hand. Fungal cultures were obtained on different nutrient media from disinfected superficial skin scrapings and fragments taken from a deep skin biopsy. Deep skin biopsy showed the presence of globose, dark fungal cells in the upper and lower dermis, sometimes in abscesses or giant cells, indicating chromoblastomycosis. All fungal fragments plated on nutrient media yielded colonies of Chaetomium funicola which was identified based on morphological observations and molecular sequence data of large ribosomal subunit rDNA. Treatment with fluconazole was ineffective. Further treatments could not be applied because of the patient’s advanced age, low compliance, and limited resources in a rural, tropical environment. For the first time, C. funicola is confirmed as an opportunistic fungus causing superficial and deep cutaneous lesions. Up to now, the only known clinical record of this species is a tentative identification as an agent of deep mycosis.