A case of chromoblastomycosis caused by Fonsecaea pedrosoi: challenge in diagnosis

Background: Chromoblastomycosis (CBM) is a chronic, granulomatous mycosis of the skin and subcutaneous tissue produced by the traumatic inoculation of various dematiaceous fungi. CBM lesions are clinically polymorphic and often misdiagnosed as multiple infectious and noninfectious diseases. Early diagnosis and prompt treatment of CBM are important to prevent further complications. This case study aims to evaluate the chromoblastomycosis caused by Fonsecaea pedrosoi as a challenge in diagnosis. Case Presentation: A male, 47 years old, came to the dermatovenereology clinic with a chief complaint of a wound on his right leg 17 years ago. The skin appeared thicker and scaly and felt rough. He also complained of pain and itch on the wound. Dermatological examination revealed multiple verrucous erythematous plaques, sized 10x20 cm, irregular with a well-defined and elevated border and black punctum. Results of potassium hydroxide, culture, and histopathology examination confirmed CBM with F. pedrosoi as the etiological agent. The patient was treated with a favorable outcome with oral itraconazole, local thermotherapy, and CO₂ laser. Conclusion: The diagnosis of Chromoblastomycosis remains a challenge because lesions are clinically polymorphic and often misdiagnosed as various infectious and noninfectious diseases. Physicians should raise awareness of CBM as one of the differential diagnoses for chronic wounds. This case also showed that the combination treatment of itraconazole with adjuvant thermotherapy and CO₂ laser had a favorable outcome.