Comorbidity and Multimorbidity of Asthma and Allergy and Intolerance to Chemicals and Certain Buildings

Objectives: We tested the hypothesis of high comorbidity between asthma/allergy and chemical intolerance (CI) and between asthma/allergy and building intolerance (BI), and high multimorbidity between asthma/allergy, CI, and BI. Methods: Population-based questionnaire data were used from 530 participants with asthma/allergy (allergic asthma, nonallergic asthma, allergic rhinitis, and/or atopic dermatitis), 414 with self-reported and 112 with physician-diagnosed CI, and 165 with self-reported and 47 with physician-diagnosed BI. Separate reference groups were formed for each of the five case groups. Results: Adjusted odds ratios varied from 4.6 to 13.1 for comorbidity, and from 6.6 to 46.4 for multimorbidity. Conclusion: The large comorbidity and multimorbidity between asthma/allergy, CI, and BI evokes the question as to whether there are similarities in underlying mechanisms between these conditions.