The Cat Allergy Culprit

The cat allergy culprit is a protein that cats produce naturally. It is invisible to the naked eye. For the most part, the protein spreads freely about the house attached to tiny particles of skin flakes, or dander, which cats shed while grooming themselves. Medical science calls the allergen Fel d1.
"The allergen is found in cats' saliva, on their pelts and in their skin," says James Sublett, clinical professor of Allergy and Immunology in the Department of Pediatrics at the University of Louisville School of Medicine. "One problem in particular is that it's a small allergen, something like two microns in size."
Sublett uses the analogy of ping-pong balls vs. basketballs. "The bigger balls fall out of the air and settle," he says, "but imagine a fan hitting a bunch of ping-pong balls and blowing them all around. Cat allergens stay in the air." Thus, he says, some people can be deathly allergic to cats but not to dogs, because the dog allergen is heavier. (Courtesy Cat Fancy, May 2007)