Furry animals are a key source of indoor allergies both for the pet owner and for sensitized persons who are exposed during normal routine activities. For these individuals, the allergens increase the risk for developing allergic rhinitis and asthma in the domestic and occupational environments. Cat sensitizations are the most common of these domestic allergies followed by dogs and horses. It is not their hair that is directly responsible for these reactions, but proteins contained in saliva, feces, or urine of the animal. For example, Fel d 1 is a major allergen primarily expressed in the cat’s salivary glands but also found in the skin and feces of animals; it is a uteroglobin related to the cat’s sexual hormones that is found in 60%-100% of all cat allergies. This “dander” sticks to animal hair during normal grooming activities and is dispersed when shed into the environment. As animal allergens are easily transported by human clothes, they can lead to downstream exposure for friends, roommates, and extended family members. For example, some evidence exists showing that exposure to cat allergens may lead to asthmatic episodes for unrelated sensitized students in the schools.
If there are recurring symptoms of itchy eyes, wheezing, shortness of breath or sneezing when exposed to a cat, it is likely that there is sensitization to common allergens associated with the cat’s dander. Consultation with an allergist would be needed to assess the degree of the patient’s allergic sensitization. This would involve a blood test that would diagnose the level of IgE that is reactive to allergens like Fel d 1. Immunotherapy is an option for patients when symptoms are not adequately controlled by medications and/or avoidance measures, when adverse effects of medications are unacceptable, or when the patient wants to reduce their long-term use of medication. This allows cat allergy sufferers to maintain their relationship with their pet or to withstand exposure during normal routine activities with associates with cats, dogs, or horses.