Tolerance develops in NSAID-induced urticaria/angioedema

(HealthDay)—Patients with nonsteroidal anti-inflammatory drug (NSAID)-induced urticaria/angioedema (NIUA) may develop tolerance to NSAIDs over time, according to a study published online Feb. 22 in Allergy.

Inmaculada Doña, from the Regional University Hospital of Malada-IBIMA in Spain, and colleagues examined NSAID-hypersensitivity over time in NIUA patients. Data were included for 38 patients confirmed as NIUA by positive drug provocation test (DPT) with acetylsalicylic acid (ASA) during 2005 to 2012 (V1). Patients were reevaluated by DPT with ASA or other NSAIDs after 60 months (V2) and after a further 18 months (V3).

The researchers found that 63.15 percent tolerated ASA and other NSAIDs at V2 (Group A), while 36.84 percent still reacted (Group B). All Group A patients remained tolerant and all Group B patients remained hypersensitive at V3. Group A had a significantly lower number of previous episodes reported at V1 (P = 0.005) and a reduced percentage of reactions induced by ASA/ibuprofen (P = 0.006). At 72 months after their last evaluated reaction (V1), group A patients developed tolerance; this interval was shorter in non-atopic patients, in those who experienced reactions one hour after NSAID administration, and for those who experienced isolated urticaria after intake of NSAIDs.

"NIUA patients may develop tolerance to NSAIDs over time, a process that seems to be influenced by atopy and type of clinical reaction," the authors write.