REDUCED PREVALENCE OF ALLERGIC DISEASES IN ADULTS WITH MULTIPLE SCLEROSIS: AN ISAAC-BASED CASE-CONTROL STUDY IN TURKISH POPULATION

Şefika İlknur KOKCU KARADAG, Nilay ÇALIŞKAN, Elif Merve HELVACI, Murat TERZİ, Recep SANCAK

Journal of Experimental and Clinical Medicine - 2026;43(2):132-136

Department of Pediatric Allergy and Immunology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Türkiye

 

Multiple sclerosis is a chronic inflammatory disease of the central nervous system involving complex immune pathways, including Th1, Th17, and regulatory mechanisms. Allergic diseases are classically associated with Th2-skewed immune responses. Although historical Th1/Th2 models suggested a possible inverse relationship between these conditions, published studies have reported conflicting results. We aimed to investigate the association between allergic diseases and multiple sclerosis in an adult Turkish population. We evaluated 32 adults with MS and 32 demographically comparable controls through structured interviews and medical record review. Allergy-related symptom questions were guided by key ISAAC Phase 3 items adapted for adult participants. Reported physician-diagnosed allergic diseases and symptom-based outcomes were analyzed separately. The study comprised 32 MS patients with a mean age of 39.4+/-9.1 years and 32 healthy controls with a mean age of 32.5+/-9.2 years. Reported history of allergic disease was present in 28.1% of MS patients and 65.6% of controls. Overall allergic disease history was less frequent in the MS group (OR 0.20, 95% CI 0.07-0.59; p=0.005). Lower frequencies of wheezing, eczema, urticaria, and nocturnal cough were also observed among MS patients. Because of the small sample size and residual age difference between groups, these findings should be interpreted cautiously. Allergic diseases were less frequently reported among adults with MS, suggesting a possible inverse association. However, given the small sample size, residual age imbalance, and the exploratory adult adaptation of ISAAC-based questions, the findings should be considered hypothesis-generating rather than causal.