Invasive Trichophyton rubrum infection occurring with infliximab and long-term prednisone treatment

A 64-year-old woman presented with erythematous plaques, tender nodules, and pustules of the dorsal right hand and both legs following long-term treatment with systemic steroids and infliximab. Skin biopsy demonstrated dermal inflammation with foci of necrosis and multinucleated giant cells containing fungal spores. Tissue culture grew Trichophyton rubrum.

To report a case that demonstrates the pathophysiology of invasive T. rubrum infection, the mechanisms of action and uses of tumor necrosis factor alpha (TNF-alpha)-inhibiting drugs, and how these drugs may increase patients' risk of invasive dermatophytosis.

Dermatophytes such as T. rubrum rarely cause invasive disease. This unusual presentation of invasive T. rubrum occurred with immunosuppression by infliximab and systemic steroids. Patients should have a thorough examination for signs of latent infection before TNF-alpha inhibitors are prescribed, including inspection of the skin and nails for signs of dermatophytosis.