The signs of an allergic reaction to cats most often resemble those of the common cold. These include symptoms of nasal discomfort like a runny nose and sneezing, itchy irritation of the eyes and nose, and respiratory distress like coughing and shortness of breath. More severe allergic reactions to cats can also include throat swelling that can cause difficulty breathing or swallowing, and swelling of the skin, especially in the face, hands, or feet, which requires immediate medical attention.
It is estimated that about 10% of the human population has a natural allergic reaction to cats, with up to one-third of all people who have other allergies also exhibiting allergic responses to cats. Unaltered male cats tend to produce the most allergic effects in people, with females and neutered males being less prone to causing allergic effects. This is likely due to the causes of an allergic reaction to cats, which can be traced to five distinct proteins produced in the feline’s shed skin and hair known as dander, saliva, and urine.
The two proteins that are known to cause the most prominent allergic reactions are Secretoglobin — Fel d 1 — produced in saliva, and Lipocalin — Fel d 4 — produced in urine. While these proteins would seem to be uncommon in the home and not widely dispersed due to their limited sources, studies have shown that they are often present nearly everywhere on furniture, walls, and in the air. Cat allergens have even been found to be common in rooms where a cat has never lived due to the fact that they are small proteins that are easily diffused throughout a confined environment. Part of the reason for their potent effect, even in small concentrations, is that cat allergens cause the human immune system to overreact in the same way that it would to combating the presence of small amounts of a virus or bacteria.
Recognizing an allergic reaction to cats often requires verification by a skin or blood test performed by a doctor. This is because cats also bring pollen and mold allergens into the home which may be the root cause of an allergic response, and other elements of a home can also cause allergic reactions where cats are present, such as dust and chemicals in the air, or contaminants produced by cat litter. Often, cleaning cat litter frequently and bathing a cat in pet shampoo will reduce allergic symptoms, which is another way of verifying the source of an allergic reaction to cats.
Treating an allergic reaction to cats when it is fairly mild, and when pet owners wish to keep the cat, can be done through several approaches. They can try to limit exposure to the cat by keeping it out of certain rooms in the house such as the bedroom. The home can also be designed to minimize buildup of allergens by choosing hard wood floors, steam cleaning carpets regularly, and using high-efficiency particulate air (HEPA) filters on furnaces and vacuum cleaners. The cat should also be cleaned and groomed on a regular basis with specially-formulated pet shampoos made to reduce protein secretions. Antihistamines for allergies can be taken as well on a regular basis by pet owners, or immunotherapy treatments can be used to build up a resistance to the allergens.