Three patients with mycetoma were successfully treated with dapsone. Nocardia asteroides was cultured from the lesions of two patients; these were the second and third patients whose cases have been reported in the United States. The histopathologic appearance of the granules in the lesions of the third patient was similar to that of the first two, although the etiologic agent could not be cultured. In all three patients, dapsone was highly effective but required prolonged administration. The absence of bony involvement in the patients contributed greatly to the good response to dapsone treatment and to the good prognosis for eradicating the latent foci. All three patients tolerated the prolonged dapsone therapy well, developing only a mild, well-compensated hemolytic anemia.
Rogers RS, Muller SA. Treatment of Actinomycetoma With DapsoneA Report of Infection With Nocardia asteroides. Arch Dermatol. 1974;109(4):529-534. doi:10.1001/archderm.1974.01630040039008