Asthma frequency and features in adults with isolated cat allergy: A retrospective study in a tertiary centre.

Introduction: Cat is a source of allergens that can cause allergic rhinitis (AR), conjunctivitis and/or asthma. This study aimed to compare demographic characteristics, frequency of asthma development, duration of asthma development, and characteristics of the patients with AR and with AR/asthma in adult patients who have adopted a cat in adulthood and have allergic symptoms after exposure to cats.

Materials and methods: Symptoms, physical examination findings, complete blood count, skin prick test (SPT) and/or specific immunoglobulin E (sp IgE) and pulmonary function test results of adult cat owners with allergic symptoms due to isolated cat allergy between January 2021 and February 2025 were retrospectively evaluated.

Result: Isolated cat allergy was detected by SPT and/or sp IgE measurement in 203 patients with allergic symptoms. Median age of the patients was 29 (18-69) years. A total of 71 patients (35%) experienced asthma and AR/ conjunctivitis symptoms upon exposure to cat allergens. Only patients with AR/conjunctivitis had been exposed to cat for median 24 (12-180) months. In patients with AR/conjunctivitis and asthma, median duration of cat exposure was 36 (12-300) months. Patients with AR/conjunctivitis developed allergic symptoms after a median of 13.5 (11-120) months following cat exposure. In patients with asthma, asthma symptoms developed after a median of 24 (11- 150) months. The severity of AR increased as the number of cats exposed to, cat sp IgE level, total IgE level and eosinophil count increased. Median eosinophil count in patients with a history of asthma attacks was 470 (110- 990) and was statistically significantly higher than in patients without a history of attacks (p= 0.014).

Conclusions: Cats have become one of the major allergens in our country in recent years. The number of patients presenting to allergy clinics with allergic symptoms after having encountered cats is increasing day by day. These patients should be advised to stay away from cats, if possible, but patients who do not agree to stay away from cats should be closely monitored for the development of asthma.