Cat Allergy: A Widespread Problem

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cat allergyCat is a well-known aeroallergen which may precipitate symptoms of allergic rhinitis and asthma in cat-sensitive individuals. When such patients are seen and evaluated, they are usually told to try and minimize their exposure to cat allergen. If they have a cat, they may be told to find a new home for the cat or to move it primarily outside. As a minimal step, they are asked to never let the cat into the bedroom.

Despite the best efforts to minimize cat allergen exposure in such patients, often they continue to have trouble. New technology to assess both airborne and settled allergen levels show that cat allergen can be found nearly everywhere in indoor environments. In this study, conducted in different locations in Europe, Heinrich and coworkers attempted to quantify the level of cat allergen in mattress dust and to determine whether there was a relationship between the levels of cat allergen in a given community and the level of specific IgE to cat.

This extensive study examined dust samples collected from approximately 3000 mattresses in 22 centers across Europe. Sieved dust samples were analyzed for cat allergen content using an ELISA assay. As might be expected, the results showed that dust levels of cat allergen were highest in those homes where cats were present.

An interesting finding, however, was that cat allergen was also detected in the mattresses of homes without cats. The community prevalence of cat ownership also correlated with the cat allergen found in dust samples from homes of non-cat owners, but it was not correlated with community prevalence of detectable specific IgE to cat allergen.

Viewpoint

This study showed that individuals who do not own cats may still be exposed to significant levels of cat allergen in their own homes, particularly if they live in communities with high levels of cat ownership.

Other studies looking at airborne levels of cat allergen using immunochemical air sampling techniques have found significant levels of cat allergen in other areas, including schools, public buildings, and office buildings. It is clear that individuals allergic to cats may have significantly more exposure to cat allergen than previously thought.

Abstract URL: http://www.medscape.com/medline/abstract/16950287