Treatment of tropical mycoses

Several subcutaneous and deep-seated mycoses are either observed more frequently in the tropical areas or are restricted to certain regions within the tropics. These mycoses include sporotichosis, chromoblastomycosis, entomophthoromycosis, eumycetoma, lobomycosis, and paracoccidioidomycosis. In sporotrichosis and paracoccidioidomycosis, therapy often results in either complete resolution or marked improvement. For decades sporotrichosis has been treated successfully with potassium iodide, but recently the triazole compounds, especially itraconazole, have proved effective and free of major side effects. The usual therapy for paracoccidioidomycosis is sulfonamides or amphotericin B; the former requires prolonged treatment, whereas the latter causes a significant degree of toxicity. Various azole derivatives (ketoconazole, fluconazole, saperconazole, and itraconazole) allow shorter treatment courses, can be given orally, and are more effective. Presently, itraconazole is the drug of choice. Chromoblastomycosis is a difficult condition to treat, especially if it is caused by Fonsecaea pedrosoi. Several therapeutic approaches have been used, including heat, surgery, cryotherapy, thiabendazole, amphotericin B combined with flucytosine, and azole derivatives, but their success has been modest. A 65% response rate has been obtained with itraconazole given for periods of 6 to 19 months; in limited trials, saperconazole appears to be more effective and requires shorter treatment courses. Only a few patients with eumycetoma respond to therapy; 70% of patients with Madurella mycetomatis respond to prolonged treatment with ketoconazole. Griseofulvin has been tried in nonresponders with partial success. Limited data in patients with Fusarium species eumycetoma indicate good responses to itraconazole. Eumycetoma caused by Pseudallescheria boydii or Acremonium species has been refractory to therapy. Therapy of entomophthoromycosis is also difficult because the diagnosis is usually established late and not all patients respond to therapy; this situation applies to infection caused by either Basidiobolus haptosporus or Conidiobolus coronatus. Although there is no consensus, African physicians prefer to use potassium iodide or trimethoprim-sulfamethoxazole. Isolated reports indicate that the azole derivatives, including the triazoles, may be effective. As for lobomycosis, all attempts at medical treatment have failed. Surgery is successful only when the lesion is small and can be fully resected; repeated cryotherapy appears to be more successful.