Effect of occlusion on Trichophyton mentagrophytes infections in guinea pigs.

The effect of occlusion and griseofulvin on the duration and severity of acute dermatophytosis was assessed in guinea pigs. Sixty guinea pigs given standard Trichophyton mentagrophytes infections were divided into 5 groups: (A) control, (B) intermittent wet occlusion, (C) continuous-wet occlusion, (D) griseofulvin, (E) griseofulvin-continuous-wet occlusion. Lesions were largest in the control group, smallest in the griseofulvin-continuous-occlusion group, and of intermediate area in the other groups. The degree of inflammation and alopecia was not affected by occlusion, but was markedly reduced or eliminated with griseofulvin. Healing of the lesions occurred more rapidly in the griseofulvin-continuous-occlusion group than in any other group. This study suggests that either occlusion of the inoculated site or oral griseofulvin markedly reduces the expected area of the fungal lesion, and occlusion together with griseofulvin shortens the duration of the lesion.