NSAID challenges during office visits safe with observation
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Key takeaways:
- NSAID hypersensitivity phenotypes depend on underlying disease.
- Most patients with aspirin-exacerbated respiratory disease have comorbid asthma.
- A third of immediate reactions did not require any treatment.
SAN ANTONIO — With a little patience, physicians can challenge and delabel NSAID hypersensitivity in the office, David A. Khan, MD, said during the 16th Annual Allergy, Asthma & Immunology CME Conference.
“NSAID hypersensitivity is complicated because it’s not one thing,” Khan, professor of medicine and pediatrics and allergy and immunology program director at UT Southwestern Medical Center, said during his presentation.
“There are multiple phenotypes of NSAID hypersensitivity, and they’re subdivided in terms of whether you have an underlying disease or not,” Khan, who also is a former president of the American Academy of Allergy, Asthma & Immunology, continued.
Asthma-exacerbated respiratory disease (AERD), for example, is characterized by sneezing, congestion, bronchospasm, laryngospasm, occasional gastrointestinal pain and flushing or urticaria. Comorbidities include nasal polyposis and chronic sinusitis as well as, for most patients, asthma. These patients are candidates for desensitization.
NSAID-induced urticaria and angioedema do not have any comorbidities, but these patients can be considered for desensitization. NSAID-exacerbated cutaneous disease also may include urticaria and angioedema among its symptoms, with active chronic spontaneous urticaria as a comorbidity. Desensitization is not advised for these patients.
“The exacerbated diseases are all cross-reactive because they’re all dependent on COX-1 inhibition,” Khan said.
When there is no underlying disease, inducible reactions to a single NSAID ranging from mild urticaria to severe anaphylaxis still may occur, Khan added. Although desensitization is possible, it probably will not be needed.
“Something just happens,” he said. “And these inducible reactions are always just hives or anaphylaxis.”
Anaphylactic reactions should be drug-specific, he said, but urticaria could be drug-specific or cross-reactive.
“You don’t know,” Khan said. “If you see a patient who has a one-time episode of hives with any NSAID, you don’t know if they’re going to react to all NSAIDs, or just that one. And so, this is where you need to do a challenge.”
Khan also noted a study of 262 challenges for aspirin, ibuprofen, naproxen and other NSAIDs, tested individually and in combination, not including AERD evaluations.
The two-step protocol began with a tenth to a quarter of a dose, followed by 60 minutes of observation. During step two, patients took the remainder of the dose, followed by 120 minutes of observation.
Potential challenge doses included 40.5 mg to 325 mg of aspirin, 50 mg to 500 mg of naproxen and 60 mg to 600 mg of ibuprofen.
The study yielded negative results (85%), immediate reactions (11.5%) and delayed (3%) reactions. A third of the immediate reactions did not require any treatment. Three patients received epinephrine, with one case of possible anaphylaxis. Two thirds of the immediate reactions happened between 60 and 120 minutes.
The authors associated positive challenges with previous reactions occurring less than 5 years before, a history of immediate reactions, a history of NSAID cross-reactivity, and chronic spontaneous urticaria.
“There’s a similar and even larger study looking at children,” Khan added.
Based on these findings and his own experience, Khan was optimistic about NSAID challenges.
“NSAID challenges can be done safely in the office,” he said. “But wait 2 hours after their last dose for observation.”