bacterial skin infection
"Though it did cure the abscess in my ear, it caused severe (I mean SEVERE) muscle/bone pain in my legs, abdomen, and diaphragm.  Later side effects were numbness with shooting pain in my left side leg and arm.  I can barely walk.  I had never taken Bacrtim before (sulfonamide).  I was also on cephilexin but I do not believe that was the problem because I've taken that without issues.  Please think twice before you take Bactrim.  For me, the benefits certainly did not outweigh the risks.  For now, I've lost my quality of life."