A case of cutaneous protothecosis successfully treated with local thermal therapy as an adjunct to itraconazole therapy in an immunocompromised host.

We report a case of human protothecosis in an immunocompromised host which was caused by Prototheca wickerhamii and was successfully treated with thermal adjunct therapy combined with systemic itraconazole therapy. A 78-year-old man taking 30 mg prednisolone daily had a 1-week history of erythematous plaques on the dorsal aspect of his right hand and forearm after sustaining a small traumatic injury. Histopathology of the lesions revealed granulomatous inflammatory changes with numerous microorganisms that had multiple septations in their cytoplasm. On the basis of mycological features and the results of the sugar assimilation test, the etiologic agent was identified as Prototheca wickerhamii. Although the lesion showed no response to the systemic itraconazole therapy and topical ketoconazole treatment, a complete resolution was achieved by the use of thermal therapy as an adjunct to systemic itraconazole.