Italian Journal of Prevention, Diagnostic and Therapeutic Medicine

Abstract

The increasing presence of cats in homes, associated with significant levels of dog and cat allergens in areas where no animals are present (homes, schools, nurseries, places of work), has contributed to an increase in the frequency of allergy to these animals in industrialized countries. Animals are therefore the third leading cause of allergic asthma, after mites and pollens. In addition to pet owners and their family members, professionals involved in animal care and research are a clearly affected group, representing up to a third of sensitized patients. Cat allergy represents a significant health problem with unresolved questions about clinical management, diagnosis, treatment and prevention. Symptoms range from mild rhinoconjunctivitis to potentially life-threatening asthmatic exacerbations. In vivo and in vitro diagnostics of cat allergy is currently based on cat dander extract. With the introduction of allergens produced by recombinant techniques, a large panel of recombinant allergenic molecules including the major cat allergen, recombinant Fel d 1, has become available for immunological investigations, diagnosis and treatment. Studies have shown that this single allergen, which belongs to the uteroglobin protein family, is at least as good as cat dander extract in identifying cat-allergic patients. Fel d 1, is produced by the skin and by salivary and lacrimal glands of the cat, is transferred to the pelt by licking and grooming. Dried saliva and dandruff are spread from the cat hair as small airborne particles into the surrounding environment, where they may cause sensitization in susceptible individuals. Fel d 1 is the dominant cause of allergic symptoms among patients sensitized to cat, and sensitization to Fel d 1 is a risk factor for developing asthma. Allergen-specific immunotherapy is the only treatment able to change the natural course of allergic disease. Immunotherapy with cat dander extracts has proved efficacious for treatment of respiratory allergy to cat.