Evaluation of penicillin hypersensitivity: Value of clinical history and skin testing with penicilloyl-polylysine and penicillin G: A cooperative prospective study of the penicillin study group of the American Academy of Allergy

Abstract: A multicenter cooperative study of almost 3,000 patients by members of the Penicillin Study Group of the American Academy of Allergy has confirmed the usefulness of skin tests to penicillin G (Pen G) and penicilloyl-polylysine (PPL) in the evaluation of penicillin hypersensitivity. Nineteen percent of 1,718 patients with a history of penicillin allergy had positive skin tests to either or both agents, vs 7% of 1,229 patients with no such history. Among patients with a history of penicillin allergy where a detailed history was available, positive skin tests were noted in 46% with a history of anaphylaxis, 17% with a history of urticaria or angioneurotic edema, and 7% with a history of a maculopapular reaction. PPL Generally gave somewhat higher reaction rates than Pen G, but both skin tests were needed to elicit the maximum number of reactors. After skin tests were completed, 379 patients were challenged with penicillin. Six percent of patients with a positive history had an allergic reaction vs 2% of patients with a negative history. However, 67% of the 9 challenged patients with a positive skin test had an allergic reaction, and half of these were immediate or early systemic reactions. Only 3% of the 346 challenged patients with a negative skin test had a reaction to challenge and only one fourth of these had early reactions thought to be possibly mediated by IgE.