Declared Penicillin Allergy and Increased Risk for MRSA and C. difficile

Several studies, some of them going back 30 years or more, have demonstrated that a history of “penicillin allergy” is frequently inaccurate or may not predict current serious allergic risk. Nonetheless, given that history, health care providers will often turn to non–penicillin-containing drugs to treat infection, fearing a severe penicillin allergic attack.

In a population-based matched cohort study using the U.K. Health Improvement Network database, researchers identified 64,141 patients with a history of penicillin allergy and 237,258 age-, sex-, and enrollment time–matched controls with no penicillin allergy history. No patient in either group had a prior history of methicillin-resistant Staphylococcus aureus (MRSA) or Clostridium diffi…