Background: Analgesic intolerance (AI) sometimes appear alone and sometimes with bronchial asthma affecting about 10% of asthmatics and sometimes before and the other times after asthma.
Objective: We investigated the possible clinical risk factors which might be affecting the transition from isolated AI to analgesic induced asthma (AIA).
Methods: A total of 344 patients admitted to Hacettepe University Hospital Adult Allergy Unit between January 1991 and March 1999 and diagnosed with AI were enrolled in this survey. Patients having AIA (group I) (n = 191) were compared with the patients having AI without asthma (group II) (n = 153). The diagnosis of AI and AIA were made by history and oral provocation tests. A standard questionnaire was filled-in for all the patients.
Results: The risk of AIA was increased with nasal polyp, and rhinosinusitis via OR's of 2.75 (95% CI: 1.09, 6.91), and 18.58 (95% CI: 9.86, 35.01), respectively. Having a pet, and ever smoking decreased the risk of AIA in the patients with AI via OR's of 0.53 (95% CI: 0.24, 1.17), and 0.37 (95% CI: 0.17, 0.80), respectively. The association of AIA and smoking was slightly modified by food intolerance (OR for ever smoked and food intolerance: 1.31, 95% CI: 0.40, 4.30).
Conclusion: There may be two different phenotypes of AI with different clinical features: one developing AIA (having nasal polyp and/or rhinosinusitis, and smoking if food allergy/intolerance is present), and the other AI without asthma (having pet, and could smoke). Findings of this study should be confirmed by further investigations.