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

BACKGROUND: 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. OBJECTIVE: 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. CONCLUSION: 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.