Mycoplasma hominis septic arthritis in a pediatric renal transplant recipient: case report and review of the literature.

Septic arthritis (SA) typically occurs in young children, often from Staphylococcus. With chronic immunosuppression, however, pathogens may be atypical. A 15-year-old African-American female developed Mycoplasma hominis SA in her right hip 2 months following cadaveric renal transplant (Tx). Her presentation was subtle and indolent, without fever or leukocytosis. Although reported in adult Tx recipients, M. hominis infections have not been described in pediatric recipients. Early immunosuppression (basiliximab, prednisone, tacrolimus, mycophenolate mofetil and Thymoglobulin) may have increased her susceptibility to M. hominis. Optimal therapy for M. hominis SA is not well established and relapses occur. This patient underwent joint incision and drainage, treatment for 8 weeks with doxycycline and levofloxacin guided by in vitro sensitivities, and a reduction in immunosuppression. She has been free of ongoing infection for 3 years with stable graft function (Cr 1.1 mg/dL) on moderate immunosuppression with prednisone, tacrolimus and MMF.