title: Skin testing to detect penicillin allergy.
abstract: Skin testing for penicillin allergy with penicillin G (Pen G), penicilloic acid (PA), and penicilloyl poly-L-lysine (PPL) was performed on 740 subjects, and the results were assessed from epidemiologic and immunologic perspectives. Approximately 95% of these patients had histories of apparent allergic reactions to beta-lactam antibiotics, and 63% were skin-test positive. The prevalence of positive skin tests was related to the time that had elapsed between clinical reactions and skin testing. Ninety-three percent were skin-test positive 7 to 12 mo after reactions, and 22% were positive 10 yr or more after reactions. Patients under 30 yr of age had a prevalence of positive skin tests 1.7-fold higher than older patients. Testing with PPL, PA, and Pen G detected 76.3%, 55.3%, and 57.1% of the positive patients, respectively. Omission of PPL, PA, or Pen G would have led to a failure to detect 25.6%, 7.2%, and 6.2% of the positive patients, respectively. Subjects with skin tests positive to penicillin often reacted to skin tests with other beta-lactam antibiotics; 73% (41 of 56) reacted to ampicillin and 51% (38 of 74) reacted to cephalothin. No serious allergic reactions were provoked by testing. None of the 83 skin test--negative patients treated with beta-lactam antibiotics immediately after testing experienced acute allergic reactions. Two patients developed mild urticaria beginning 3 and 5 days into therapy. One skin test--negative patient experienced urticaria 3 hr after receiving oral penicillin 6 mo after skin testing. This patient's skin-test status immediately before therapy was unknown. These results support the position that testing with PPL, PA, and Pen G is a rapid, safe, and effective method for identifying patients at risk, or not at risk, for allergic reactions to penicillin.
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging; D000667:Ampicillin / Q000009:adverse effects; D044482:Benzeneacetamides; D044383:Black People; D002228:Carbenicillin / Q000009:adverse effects; D002512:Cephalothin / Q000009:adverse effects; D004342:Drug Hypersensitivity / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D007428:Intradermal Tests; D007769:Lactams / Q000009:adverse effects; D008297:Male; D010397:Penicillanic Acid / Q000009:adverse effects / Q000031:analogs & derivatives; D010400:Penicillin G / Q000009:adverse effects / Q000031:analogs & derivatives; D010406:Penicillins / Q000009:adverse effects*; D011107:Polylysine / Q000009:adverse effects / Q000031:analogs & derivatives; D012882:Skin Tests; D013997:Time Factors
chemical_list: D044482:Benzeneacetamides; D007769:Lactams; D010406:Penicillins; D011107:Polylysine; C016262:benzylpenicillenic acid; C003058:penicilloyl polylysine; D000667:Ampicillin; D010397:Penicillanic Acid; D002228:Carbenicillin; D010400:Penicillin G; D002512:Cephalothin