Prevalence of occupational allergy to laboratory animals in two towns of northern and central Italy

BACKGROUND: Laboratory animal allergy (LAA) is a well known occupational hazard for workers employed in biological and medical research institutes, but few Italian data on this disease exist. OBJECTIVES: The aim of our study was to evaluate the prevalence of LAA in 45 workers in Trieste (NE-Italy) and in 80 workers in Perugia (Central Italy) and to assess factors predisposing to sensitisation among subjects occupationally exposed to animals. METHODS: All subjects underwent a physical examination and responded to a standardized questionnaire for the evaluation of allergic respiratory symptoms and exposure data. Skin prick tests with common allergens and with hair extract from laboratory animals were performed and specific IgE was measured. Atopy was defined as positive skin prick test to common allergens. RESULTS: There were 60% atopic subjects in Trieste and 55% in Perugia and sensitisation to laboratory animal hair was found in 24.4% subjects in Trieste and in 35% in Perugia. The prevalence rates of LLA were respectively 11.1% and 11.2%; 2.3% and 3.7% complained of asthma while 8.9% and 7.5% complained of rhinitis. The resulting symptoms were significantly related to skin prick tests that were positive to laboratory animal hair (odds ratio (OR) = 7.64; 1.83-44.5), to skin prick test positivity to common inhalant allergens (OR = 5.29; 1.09-50.2), to common allergic symptoms (OR = 3.95; 1.05-18.2) and to exposure time exceeding 5 hours per day (OR = 5.45; 1.31-22.0). CONCLUSION: The role of atopy and of exposure time in causing LLA was confirmed and the need of prevention measures to reduce exposure in people at risk was discussed.