D2.23 - The Natural Course Of Allergic Rhinitis In Cat Owners With Cat Allergy

Limited information exists on the course of allergic rhinitis (AR) caused by Felis domesticus allergens in individuals who continue to keep domestic cats. This study aims to determine the rate of individuals who discontinue cat ownership after diagnosis and compare treatment responses between those who keep cats and those who do not.

The study included AR patients with cat allergies diagnosed at a tertiary care clinic between January 2010 and December 2021. The primary objective was to assess the rate of cat removal after diagnosis, and the secondary objective was to compare changes in Visual Analog Scale (VAS) scores for nasal symptoms at 6-month follow-up between those who kept or removed cats, and evaluate risk factors for persistent AR symptoms.

A total of 126 patients, 92 (73.0%) of whom were female, participated in the study, with a median age of 31 (range: 18.0-64.0) years. The mean duration of cat ownership was 57.6 ± 50.2 months, and symptoms appeared 14.3 ± 28.6 months after bringing the cat into the household. Of the patients, 42 (33.3%) stopped keeping their cats, mainly due to allergy (27, 65.9%), with a median symptom improvement time of 21 (range: 3.0-672.0) days.

At 6 months, no significant difference was observed between the cat removal and no removal groups for nasal congestion, discharge, itching, and sneezing scores (p = 0.169, p = 0.431, p = 0.108, p = 0.167, respectively). Patients who removed the cat discontinued medical treatment for rhinitis at a higher rate compared to those who kept the cat (p = 0.003). Smoking history (OR = 19.47, [95% CI] = [5.53–68.59]; p < 0.001) and duration of cat ownership (OR = 1.01, [95% CI] = [1.00–1.02]; p = 0.025) were identified as significant risk factors for persistent AR in the multivariate logistic regression analysis.

Two out of three cat-allergic patients continued to keep cats after diagnosis. Cat-allergic patients who continued keeping cats had similar symptom scores to those who did not, but those who removed the cat had a significantly higher rate of discontinuing rhinitis medications. Smoking and duration of cat ownership were the significant risk factors for persistent AR.