Allergy to laboratory animals among animal handlers

Objective: To determine the prevalence among laboratory animal handlers of allergy to laboratory animals and of asthma and the factors associated with their development. Design: A cross-sectional survey. Setting: Teaching and research institutions in Sydney, between January 1989 and December 1992. Participants: Laboratory animal handlers (teaching and research staff, animal house workers and animal husbandry students and teachers). Main outcome measures: Duration of exposure to laboratory animals, allergic symptoms on contact, skin reactivity to laboratory and domestic animal allergens and evidence of current asthma. Results: 228 subjects were surveyed. Allergy symptoms occurred in 73 (56%) of the subjects exposed to laboratory animals for three months or more. This group also had significantly higher prevalences of skin reactivity to laboratory animal allergens (62%) and bronchial hyperresponsiveness (21%) than those with shorter exposure (14% and 8%, respectively). Atopic subjects exposed to laboratory animals (particularly those sensitised to domestic animals) and animal attendants (with a high intensity of exposure to laboratory animals) had significantly higher frequencies of skin reactivity to laboratory animals and asthma than other subjects (77% and 30%, respectively, among exposed atopic subjects and 84% and 33%, respectively, among animal attendants). Conclusions: Allergy to laboratory animals is an occupational hazard among laboratory animal handlers, especially for those who are atopic and sensitised to domestic animals, and may lead to the development of asthma. Screening for atopy and skin reactivity to laboratory animals before and during employment would enable those at risk to take precautions.