Penicillin and Beta-Lactam Drug Allergy

Up to 20% of patients experience adverse drug reactions with 32% fatality rate. Most reactions are dose-dependent, or related to side effects, or drug interactions. About 10% of patients report penicillin allergy, which typically leads to alternative prophylactic antibiotics, but doing so, places the patient at increased risk of surgical site infection. However, 90% of patients labeled as penicillin allergic can tolerate penicillin. Thus, appropriately delabeling penicillin allergy is a goal. When history of Penicillin allergy raises a concern, penicillin skin testing and subsequent graded-dose challenge is indicated but must be in a safe setting, under supervision of an allergist. Drug desensitization for a Penicillin allergic patient is justified if no appropriate alternatives to Penicillin exists Cephalosporins may be used if there is history of unverified nonanaphylactic penicillin allergy. Drug allergies may manifest in a variety of ways. Serum sickness is triggered by a foreign protein, with fever, rash, edema, arthralgias, and lymphadenopathy, and treated most importantly by withdrawing the agent, and non-steroidal anti-inflammatories and/or corticosteroids. Cutaneous adverse drug reactions focus on skin, nails, hair, and glands and can range from mild cutaneous maculopapular exanthema to life-threatening cutaneous reaction, often a part of serious systemic disease. The key treatment is identification and discontinuation of causative drug.