Clinical Characteristics of NSAID Drug Allergies and Predictive Value of the History for Oral Drug Challenge Outcomes
Monday, March 7, 2016
South Exhibit Hall H (Convention Center)
Rebecca Koransky, MD, Denisa Ferastraoaru, MD MSc, Elina Jerschow, M.D., M.Sc.
Rationale: NSAID allergies are among the most frequently reported drug allergies and have significant implications for patients.

Methods: We conducted chart reviews and phone interviews of patients seen in our Drug Allergy Clinic from 2009-2014 who underwent an oral drug challenge for a self-reported NSAID allergy.

Results: 41 NSAID challenges in 35 patients were reviewed, 37 challenges were negative. The majority of patients were female (86%), of Hispanic ethnicity, and ages 41-60. Most reported one single episode of NSAID allergy and at least one other allergic reaction to an unrelated medication. The most frequent reaction was urticarial alone (34% of patients) followed by angioedema (22% of patients) and most reactions took place within 5 hours of ingesting medication. Of patients with urticarial rash alone, 0 patients had positive challenge. Of patients with angioedema alone, 10% had positive challenge, and of patients with both, 40% had positive challenge. On follow up calls, 18 patients were reached, and 16 participated. Of these patients, 9 were tolerating the medication and 7 were not taking medication at all. Of patients currently not taking the medication, one third developed delayed adverse reaction after challenge (angioedema and vomiting), one third developed a repeated adverse reaction on re-exposure (angioedema), and the rest were afraid of trying the medication at home.

Conclusions: A history of urticarial rash attributed to NSAIDs was most likely associated with a negative challenge. Despite negative oral challenge in the office to NSAIDs, only 60% of patients continued to safely take the medication.