Prospective,multicenter clinical trial to validate new products for skin tests in the diagnosis of allergy to penicillin

Background: allergy to penicillin is the most commonly reported type of drug hypersensitivity. diagnosis is currently confirmed using skin tests with benzylpenicillin reagents,ie,penicilloyl-polylysine (ppl) as the major determinant of benzylpenicillin and benzylpenicillin,benzylpenicilloate and benzylpenilloate as a minor determinant mixture (mdm). objective: to synthesize and assess the diagnostic capacity of 2 new benzylpenicillin reagents in patients with immediate hypersensitivity reactions to β-lactams: benzylpenicilloyl octa-l-lysine (bp-ol) as the major determinant and benzylpenilloate (penilloate) as the minor determinant. methods: prospective multicenter clinical trial performed in 18 spanish centers. efficacy was assessed by detection of positive skin test results in an allergic population and negative skin test results in a nonallergic,drug-exposed population. sensitivity,specificity,and negative and positive predictive values were determined. results: the study sample comprised 94 allergic patients: 31 (35.23%) presented anaphylaxis,4 (4.55%) anaphylactic shock,51 (58.04%) urticaria,and 2 (2.27%) no specific condition. the culprit β-lactams were amoxicillin in 63 cases (71.60%),benzypencillin in 14 cases (15.89%),cephalosporins in 2 cases (2.27%),other drugs in 3 cases (3.42%),and unidentified agents in 6 cases (6.82%). the results of testing with bp-ol were positive in 46 cases (52.3%); the results of testing with penilloate were positive in 33 cases (37.5%). when both reagents were taken into consideration,sensitivity reached 61.36% and specificity 100%. skin testing with penilloate was significantly more often negative when the interval between the reaction and the study was longer. conclusions: the sensitivity of bp-ol and penilloate was 61%. considering that amoxicillin was the culprit drug in 71% of reactions,these results indicate that most patients were allergic to the whole group of penicillins. these data support the use of benzylpenicillin determinants in the diagnosis of allergy to β-lactams,even in predominantly amoxicillin-allergic populations. © 2013 esmon publicidad.