Intolerance to nonsteroidal anti-inflammatory drugs might precede by years the onset of chronic urticaria

Background: Recent studies have found that most otherwise normal subjects with a history of acute urticaria induced by several nonsteroidal anti-inflammatory drugs (NSAIDs) show a wheal-and-flare reaction on intradermal injection of autologous serum. This phenomenon has been previously observed in patients with chronic urticaria (CU) and suggests a possible common background in CU and NSAID-induced urticaria. A relationship between these 2 conditions is further suggested by the fact that up to 30% of patients with CU have a worsening of their skin disorders after the ingestion of chemically unrelated NSAIDs. Objective: I sought to assess whether otherwise normal subjects with multiple or single NSAID intolerance show a propensity to have CU. Methods: Two hundred eighty otherwise normal patients with an unequivocal history of acute urticaria induced by NSAIDs seen during the last 10 years were studied. On the basis of both clinical history and oral challenge tests with at least 2 alternative NSAIDs, the patients were classified as having single or multiple NSAID intolerance. All the patients were reevaluated within the end of 2002, 1 to 10 years after the first visit, to assess the onset of CU. One hundred allergic adults without a history of CU and of drug allergy followed up for I to 10 years were used as control subjects. Results: One hundred fifty-nine and 121 patients were finally considered as having single or multiple NSAID intolerance, respectively. At the follow-up visit, 93 (33%) of 280 patients had CU. The prevalence of CU was very similar in subjects with single or multiple NSAID intolerance (48/159 [30%] vs 45/121 [37%], respectively; P = not significant). Only 1 (1%) of 100 atopic control subjects had CU during the follow-up period (P < .001). Among single NSAID reactors, patients who had CU had a significantly higher prevalence of intolerance to aspirin than those who did not have CU (36/48 [75%] vs 41/111 [37%], P < .001), whereas the latter had a markedly higher prevalence of intolerance to pyrazolone drugs (52/111 [47%] vs 10/48 [21%], P < .01). Altogether, only 12 (15%) of 82 patients intolerant to drugs other than aspirin versus 36 (47%) of 77 aspirin reactors had CU (P < .001). Conclusion: NSAID intolerance might precede the onset of CU by years. Both multiple and single NSAID reactors with a history of aspirin-induced:urticaria seem at higher risk for CU than patients with a history of single intolerance to NSAIDs other than aspirin.