Cat and dog allergy and total IgE as risk factors of laboratory animal allergy

Background: Laboratory animal workers are at high risk of developing occupational allergy. In many cases the severity of allergy symptoms makes further work with laboratory animals impossible. Objective: This study was designed to estimate prevalence rates of sensitization and symptoms of allergy in a population of laboratory animal workers and to determine the association between various host factors and these prevalence rates. Methods: A cross-sectional survey was undertaken in 540 workers at eight facilities in the Netherlands. All participants completed a questionnaire and underwent skin prick testing with common and occupational allergens. In addition total and specific IgE measurements were obtained. Results: Prevalence rates of allergy symptoms caused by working with vats and mice were 19% and 10%, respectively. Symptoms, especially chest tightness, were strongly related to sensitization. Rat and mouse allergy, defined as symptoms of allergy accompanied by specific atopic sensitization were highly associated with elevated total IgE, reported adverse reactions, and positive skin prick test responses to common allergens. This relationship could be explained by a response to cat or dog allergens. Conclusions: Allergy to cats or dogs seemed to be an important risk factor for laboratory animal allergy, whereas allergy to pollen or house dust mite, in the absence of cat and dog allergy, appeared to be insignificant. More conclusive evidence about cat and dog allergy preceding laboratory animal allergy can only be provided after analysis of follow-up data.