Cat sensitization according to cat window of exposure in adult asthmatics

Summary Background In adults, there is limited information on tolerance to cat, which may be reflected by high IgG4 without IgE sensitization. Early exposure to cat may play a critical role. Objective The aim was to assess among adults the association of Fel d 1 IgG4, Fel d 1 IgE, skin prick test (SPT) response to cat and pet‐related symptoms in relation to exposure to cat considering the period of exposure. Methods SPT response to cat, specific IgE and IgG4 to Fel d 1 were assessed in 167 asthmatics recruited in chest clinics (40 years of age in average) from the French Epidemiological study on the Genetics and Environment of Asthma (EGEA). Childhood and/or current exposure to cat were studied retrospectively. Results IgG4 was higher in relation to current cat exposure (0.53 vs. 0.09 ng/mL; P