Penicillin allergy might not be very common in subjects with cephalosporin allergy

• Published in: Journal of allergy and clinical immunology Vol. 127; no. 6; p. 1638
• Main Author: Macy, Eric, MD, MS
• Format: Journal Article
• Language: English
• Published: United States Mosby, Inc 01.06.2011; Elsevier Limited
• Subjects: Allergies; Allergy and Immunology; Amoxicillin - adverse effects; Amoxicillin - immunology; Ampicillin - adverse effects; Ampicillin - immunology; Cephalosporins - adverse effects; Cephalosporins - immunology; Cross Reactions; Drug Hypersensitivity - diagnosis; Drug Hypersensitivity - immunology; False Positive Reactions; Humans; Immunoglobulin E - blood; Penicillin; Penicillins - adverse effects; Penicillins - immunology; Skin Tests - methods
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1016/j.jaci.2010.12.1125

The threshold used in the article for calling a penicillin skin test result positive was 3 mm, instead of the 5 mm specified in the package insert for Pre-Pen and used in the original articles on penicillin allergy skin testing.2,3 The use of 3 mm as a positive threshold has been shown to produce much higher rates of positive penicillin skin test results in female subjects compared with use of a 5-mm threshold.4,5 The commercial anti-penicillin IgE fluorometric enzyme immunoassays used to detect penicillin "allergy" have been shown not to correlate to penicillin skin test results and not to predict positive oral amoxicillin challenge results.5 The high-dose amoxicillin used (20 mg/mL) for skin testing is an irritating concentration and requires a nonphysiologic pH to stay in solution.