Plantar Trichophyton rubrum infections may cause dermatophytids on the hands.

Over a 2-year period, we saw 37 patients with a diagnosis of dermatophytid on the hands based on 1) culture-proven dermatophytosis on one or both feet; 2) symmetrical, secondary vesicular eruptions on the fingers and/or palmar aspects of the hands; and 3) a resolution in both areas of involvement after treatment of the dermatophytosis on the foot. During the study period, 128 patients had culture-proven dermatophytosis of the feet caused by Trichophyton rubrum. Nine of these (7%) developed dermatophytid. Seventy-eight patients had dermatophytosis of the feet caused by Trichophyton mentagrophytes. Twenty-seven of these (35%) developed dermatophytid. One of 6 patients infected on the feet with Epidermophyton floccosum developed dermatophytid.