In consultation the authors were requested to evaluate a middle-aged diabetic woman for an apparent episode of biliary sepsis. The patient had been admitted to the dermatology service with a four-day history of rash and pruritus. This was initially thought to represent an allergic reaction to dicloxacillin in someone with a previous history of penicillin hypersensitivity. Persistent right upper quadrant pain, fevers, elevations of serum alkaline phosphatase, and a radionuclide scan which did not demonstrate a functioning gall bladder led to a cholecystectomy for acute cholecystitis and possible biliary sepsis. This diagnosis was not confirmed. Ultimately, this case illustrated the need to review carefully recent changes in any patient's drug regimen. Reactions to commonly prescribed agents may cause syndromes which are difficult to distinguish from episodes of apparent sepsis.