By Dr. Massoud Mahmoudi

Cats are sweet and playful animals that are fun to have as pets. Do not forget, however, that these cuties can also cause a life-threatening condition in sensitized individuals.

There have been several theories on how that sensitization develops and how to prevent it. The conventional thought used to prohibit children from keeping cats. The rationale was that repeated exposure to cats might make children allergic. Newer studies have found just the opposite: Keeping cats may give immunity to children as they are growing up.

It’s true that cats are clean pets and easily potty-trained, but by licking themselves, they spread allergens all over their bodies. Inhalation of airborne dander or hair can cause health hazards in sensitized individuals.

The symptoms of cat allergy develop upon frequent exposure to cat allergens. This exposure is either direct, like holding the cat, or indirect, such as repeated inhalation of cat dander.

Some people may develop symptoms at work because some companies allow employees to bring their pets with them. A colleague who carries the dander and hair on his or her clothes can also expose sensitive people to cat allergens.

Symptoms generally include stuffy and runny nose, watery and itchy eyes or wheezing and shortness of breath.

You can develop allergies to any cat, but it’s easier with some types than with others. It has been reported that darker cats can cause more allergies than brighter-colored cats. Some of my patients have mentioned problems with longer-haired cats. If you like to keep a cat, you may choose a cat with a brighter color and shorter hair.

Symptoms due to direct contact with cats may include skin irritation, itching and hives. Symptoms that result from inhalation of airborne allergens may include red, watery, itchy eyes, nasal congestion, runny nose, sneezing, cough, shortness of breath and wheezing.

Removal of cats from the home environment is the ideal control measure to prevent allergic symptoms. But because of the emotional connection of owners to their pets, this is almost always impractical. An allergic person contemplating adopting cats for family members should seriously consider the decision.

You can limit your exposure by setting boundaries. Keep your cat in an outdoor environment. If you want to keep the cat indoors, try to keep it out of your bedroom. Close your bedroom vent. The cat dander can be transported to your bedroom via an open vent.

Washing the cat is an option. This is of limited value in dealing with allergens, but it may temporarily control spreading of the contaminated dander.

Medications are a temporary way of controlling the symptoms. They include antihistamines, nasal steroid sprays and bronchodilators (inhalers that open the airways).

But the only real treatment for cat allergies is an allergy vaccination. It consists of injecting cat allergen extract, a commercially prepared reagent, in increasing increments under the skin.

Such injections are administered in regular intervals. The injected allergens trigger the immune system to build up immunity against cat allergens. The period of vaccination is three to five years, and the shots can remain effective for years or even a lifetime after discontinuing the injections. Following the previously mentioned control measures, can extend the benefit of allergy shots.

Dr. Massoud Mahmoudi is an assistant clinical professor in the division of allergy and immunology at the UC San Francisco’s Department of Medicine and is in private practice, with offices in Los Altos and Los Gatos. E-mail him questions at doctormahmoudi@yahoo.com.