Laboratory animal allergies (LAA) are significant occupational hazards for researchers and staff that work with laboratory animals. Most workers that develop LAA will do so within one to three years of first exposure, and symptoms usually begin with sneezing and a runny nose, itchy/watery eyes, and/or rashes.1 Rats and mice are the most common causes of LAA because these lab animals are used more frequently than others, and not necessarily because other lab animals are less allergenic.

Risk of LAA Development

• There are four risk groups that you can fall in:
• Normal: Those with no evidence of allergies. ~10% will develop allergic reactions to lab animals.
• Atopic: Those with pre-existing allergies. Up to 73% will develop allergic reactions to lab animals. Will eventually develop symptoms from repeat exposure.
• Asymptomatic: Those with IgE antibodies to allergenic animal proteins. Up to 100% will develop allergic reactions to lab animals. Continued high exposure will eventually cause allergic symptoms.
•  Symptomatic: Those with clinical LAA symptoms when exposed to allergenic animal proteins. 100% will develop allergic reactions to lab animals which can lead to permanent impairment.3

Exposure and Occupational Tasks That Favor LAA Development

Exposure and Occupational Tasks That Favor LAA Development Although it is unclear what specific exposure levels will cause symptoms and sensitization, epidemiological studies have shown that the greater the animal allergen exposure, the more likely you will develop work-related symptoms.2 See Figure. Since allergens are found in the urine, saliva, dander, fur, and serum of experimental lab animals, the highest exposures occur among cage changers, room cleaners, and animal feeders.2 Although exposure levels primarily depend on job activity, allergens can remain airborne for long periods of time (rat allergens can remain airborne for 60+ minutes after disturbance).2 Once airborne, allergens can be carried for substantial distances throughout the animal facilities, indirectly exposing other workers.2 Therefore, it is important to use the appropriate controls and follow the appropriate work practices to protect not only yourself, but others.