Trichophyton rubrum showing deep dermal invasion directly from the epidermis in immunosuppressed patients.

Trichophyton rubrum is the most widely encountered dermatophyte infection, and is usually regarded as exclusively keratinophilic often leading to chronic cutaneous and nail infections, even in healthy individuals. We present three patients with acute leukaemias, with ill-defined pre-existent cutaneous eruptions that were treated with a potent topical corticosteroid. All three patients received aggressive marrow toxic chemotherapy. These patients had progression of their cutaneous disease, which showed deep dermal invasion of T. rubrum, invading directly from the epidermis with no evidence of systemic spread. We conclude that systemic pancytopenia, in association with prolonged local immunosuppression, may increase the risk of direct dermal invasion of dermatophyte infections. However, even in these patients, the risk of systemic spread still appears very low. Amphotericin B did not appear effective in treating these dermatophyte infections.