Eosinophilic pleural effusion due to cloxacillin and piperacillin/tazobactum

A young male was treated for right-sided pneumonia with cloxacillin and piperacillin/tazobactam. As he was recovering from the pneumonia he developed left-sided pleuritic pain and pleural effusion. At thoracocentesis an exudative pleural effusion contained 16 percent eosinophils with a simultaneous 28 percent peripheral eosinophilia. An allergic reaction to penicllins was thought to be the cause. After withdrawal of those medications and institution of prednisolone a rapid resolution was seen of symptoms, signs, peripheral eosinophilia and radiological abnormalities