Frequency of allergic rhinitis to laboratory animals in university employees as confirmed by chamber challenges

Background: Occupational risk for laboratory animal allergy (LAA) is well known, but prevention is often insufficient and new cases keep appearing. Methods: A questionnaire on work-related symptoms was sent to all laboratory animal workers in Kuopio University. Subjects with rhinitis were invited to an examination for LAA, which consisted of an otorhinolaryngological examination and skin prick testing (SPT) with 16 common environmental allergens and two to five relevant laboratory animals. In cases of occupational sensitization, a challenge test was performed. Results: The questionnaire was completed by 156 of 245 (64%) subjects. Rhinitis was reported by 65 of the respondents (42%) of whom 47 were examined for LAA. The duration of exposure before the onset of rhinitis varied from 1 month to 18 years. Twenty-seven persons (57%) had a history of some previous atopic symptoms. Forty subjects (85%) showed positive reactions in SPT, 24 (51%) for laboratory animals. Fifteen of the 26 animal challenge tests performed were positive, confirming the diagnosis of occupational allergic rhinitis in three subjects, occupational dermatitis in five and both diseases in seven subjects. The frequency of occupational allergic rhinitis among all participants was 10 of 156 (6%). Conclusions: Atopic constitution and work-related sensitization were common in rhinitic laboratory animal workers. Occupational allergic disease was diagnosed in nearly every third case.