title: Improvements in an oral aspirin challenge protocol for the diagnosis of aspirin hypersensitivity.
abstract: Oral aspirin challenge (OAC) is used to confirm aspirin hypersensitivity (AHs) but there is no consensus on a standardized protocol. As a prior clinical history of adverse reactions to aspirin is poorly predictive of a positive result from formal aspirin challenge, many patients have an OAC performed. We retrospectively identified and prospectively validated how a 1-day OAC protocol could be modified, and patient selection improved, to deliver a safe and more efficient service. In a retrospective audit of 45 OACs using a 2 h dose interval, all reactions occurred within 90 min of the threshold dose. Forty OACs were then performed using a 90-min dose interval. This reduced the mean duration of a positive and negative OAC from 6 to 5 h and from 8 to 6 h, respectively. Histories of multiple manifestations of AHs were found in 91.6% (11) of those with asthma, 87.5% (7) with angiooedema, 70.6% (12) with rhinosinusitis, 63.6% (7) with chronic non-vasculitic urticaria and all with anaphylaxis, who developed a positive OAC. None of those with anaphylaxis, 8.3% (1) with asthma and 12.5% (1) with angiooedema, with a positive OAC, had a history of a single manifestation of AHs. The efficiency of an OAC service can safely be improved by reduction of the dose interval from 2 to 1 (1/2) h, and more targeted patient selection, as the likelihood of a positive OAC increases among patients with a history of asthma, angiooedoema or anaphylaxis with multiple manifestations of AHs.
authors.affiliation: Department of Asthma, King's College London, Guy's Hospital, London, UK. cormitron@yahoo.com
authors.forename: L J
authors.initials: LJ
authors.lastname: Cormican
authors.forename: S
authors.initials: S
authors.lastname: Farooque
authors.forename: D R
authors.initials: DR
authors.lastname: Altmann
authors.forename: T H
authors.initials: TH
authors.lastname: Lee
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000707:Anaphylaxis / Q000175:diagnosis; D000799:Angioedema / Q000175:diagnosis; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000009:adverse effects; D001241:Aspirin / Q000008:administration & dosage* / Q000009:adverse effects; D001249:Asthma / Q000175:diagnosis; D001986:Bronchial Spasm / Q000139:chemically induced; D002908:Chronic Disease; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D012220:Rhinitis / Q000175:diagnosis; D014581:Urticaria / Q000175:diagnosis
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin