METHODS
Study Population
This prospective case-control study was conducted with 130 children aged 3-17 years with respiratory allergic diseases including asthma, allergic rhinitis, both together, and cat sensitization (CS group), between January 2022 and November 2023 in a tertiary referral center.
All children with cat sensitization while under follow-up by the pediatric allergy department with diagnoses of asthma and/or allergic rhinitis and whose diseases had been under control for at least three months of treatment were enrolled in the study. Age- and sex-matched healthy controls (HC group, n=70) who had presented for routine health checks were accordingly recruited from the general pediatric outpatient clinic.
CS group was divided into three groups according to their diagnoses. The first group consisted of patients with asthma (Group I, n=26), the second of patients with allergic rhinitis (Group II, n=47), and the third of patients with co-existent asthma and allergic rhinitis (Group III, n=57). They were also divided into two subgroups according to domestic cat exposure (Group Do+, n=12) or non-exposure (Group Do-, n=118).  They were further subdivided into two groups on the basis of age, the first consisting of pre-school age children (3-6 years, n=25), and the second of school-age children and adolescents (7-17 years, n=105). Additionally, were finally assigned into two groups based on treatment steps for asthma, the first consisting of children under step 2 treatment (n=34) and the second of those under step 3-4 treatment (n=49).