Challenge Test Results in Patients With Suspected Penicillin Allergy, but No Specific IgE

Abstract

PurposePatients with a history of allergic reaction to penicillin, but with no detectable specific IgE, are common and pose a dilemma. Challenge tests are considered to be the diagnostic gold standard. The aim of this study was to identify subgroups of patients with very low risk for reactions who could be safely tested using a more rapid and simple procedure.MethodsA total of 580 consecutively referred adult patients with a history of non-serious cutaneous allergic reactions to penicillin, but with no IgE, were challenged with therapeutic doses of penicillin V (phenoxymethylpenicillin), penicillin G (benzylpenicillin), or both.ResultsOnly 14 of 580 patients had a positive challenge test. In 11 of the 14, a reaction to challenge occurred within 2 hours, and none were anaphylactic. The year of the original reaction was known for 555 patients; a positive challenge was seen in only 0.4% of those with an original reaction >15 years before challenge, but in 4.6% of those with a more recent original reaction (P=0.001). Onset of a reaction within the first day of the original exposure was a predictive factor for a positive challenge (P=0.001) in patients challenged within 15 years of the original reaction.ConclusionsAmong suspected penicillin-allergic patients with non-severe skin reactions and no detectable specific IgE, the subgroup of patients who originally reacted more than 15 years previously had very low risk for reacting to a challenge. The risk was higher in patients with a more recent original reaction, especially if the symptoms had occurred within the first day of exposure.

Vancomycin Prophylaxis for Total Joint Arthroplasty: Incorrectly Dosed and Has a Higher Rate of Periprosthetic Infection Than Cefazolin

“…The International Consensus on PJI recommends that patients with nonanaphylactic penicillin allergy can safely receive a first-or second-generation cefazolin [12]. The relatively high rate of crossreactivity of cephalosporins with penicillins that traditionally was believed to be approximately 10% has been questioned recently with multiple studies estimating that up to 90% of patients reporting an allergy are actually able to tolerate penicillin and its derivatives; thus, true crossreactivity has been demonstrated to be as low as 1% [6,8,13]. Some authorities believe that cephalosporins can be given to those with anaphylactic penicillin allergy safely in a controlled environment like the operating room [3].…”

Towards a more precise diagnosis of hypersensitivity to beta‐lactams — an EAACI position paper

“…Nevertheless, according to some studies 77,84,86,95,97,98,103,107,108 (b) Some groups consider the tolerance of a MSUD or DTD enough to exclude a delayed hypersensitivity. 18,29,73,74,80,87,89,92,93,97,98,103,[106][107][108] In the related studies, 18,29,73,74,80,87,89,92,93,97,98,103,[106][107][108] the rate of positive responses to DPT with suspected BL ranged from 0% 29,89 to 7.7%. 106 Other groups believe that a too short exposure to BL (in terms of days) can be responsible for false-negative DPT, this being the rationale for performing DPT with a duration of 2-5 days [69][70][71][75][76]…”

“…DPT have been recommended by both the European guidelines 22,30,31,67,68 and the US practice parameter 35 as a part of the BL allergy workup. However, only the European guidelines 22,30,31,67,68 emphasized their role in the establishment of a firm diagnosis of During the last decade, DPT with the suspected BL have been performed in series larger than 100 subjects involving either pediatric [69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86] or adult 29,58,[87][88][89][90][91][92][93][94][95][96][97][98][99] populations or both, 18,100-109 highly enhancing our knowledge on the usefulness and safety of this diagnostic tool in BL allergy workup. This knowledge has contributed to achieving agreement on several areas of the general principles for DPT (high/strong) ( Table 5).…”

Management of allergy to penicillins and other beta‐lactams

“…• A clinical history of penicillin allergy in the more distant past (>15 years) is associated with only a very low risk (0.4%) of reacting on drug challenge [50].…”