Cat Allergies Raise the Dander of Sensitive Fliers

Christine Tung of West Los Angeles has always been allergic to cats, but in recent years her symptoms have worsened. After visiting a home with a cat in residence, she wound up in the emergency room because she was having trouble breathing. Now she hears that cats are allowed to travel in the passenger cabin of airplanes, and she wonders whether she should be worried on her next trip.

Tung has lots of company. About 10% of the population is allergic to cats or dogs (or both), according to the American Academy of Allergy, Asthma & Immunology, and allergies to cats are twice as common as allergies to dogs. (There are 59.1 million cats in American households, and 52.9 million dogs, according to the American Veterinary Medical Assn.)

Among sensitive people, exposure to pet allergens can cause swelling and itching of the membranes that line the eyes and nose, as well as a rash and, if the allergens are inhaled, breathing problems. In some people with asthma, cat contact can trigger an attack.

So it’s understandable that some air travelers want to be sure cats aren’t sharing their air space aloft.

Although there is no way to guarantee the cabin will be pet-free, an allergic traveler can take steps to minimize exposure or symptoms.

Start by asking questions when you book the flight. Most airlines limit the number of pets (which must be kept in carriers) in the cabin--usually one in first class and two or three each in the business and coach cabins.

Some reservation agents can tell the allergy-prone traveler whether cats or dogs are booked on a flight and can make a seat assignment far away. Reservation agents who don’t have that information usually advise the traveler to ask at the gate and request a seat change if necessary.

Allergies to cats seem to be increasing, says Dr. Sheldon Spector, a Los Angeles allergist and UCLA clinical professor of medicine. Why? Cats are becoming a more popular household pet, he says, and people who may not have known they are allergic seem to be keeping closer contact with their cats--letting them sleep on the bed, for instance.

Sensitivity to cats varies greatly, Spector says, so it’s impossible to advise airplane travelers about how many rows constitutes a safe distance from a flying feline.

But proximity is only part of the story. “You don’t even need a real cat” to have an allergic reaction, Spector says. “You could be sitting next to someone who has cat dander all over his clothes.”

Cat dander, the minute scales that contain the allergen, is hardy and travels well. In one study, researchers measured the levels of cat and dog allergens in schools and found them higher than the levels in homes without pets.

In another study, researchers found that wool sweaters attracted the most cat allergens.

In a plane equipped with the newer filters, the air filtering system should take care of many circulating cat allergens, experts say. The size of a typical cat allergen is about one to seven microns, says Spector, citing a respected textbook on allergies. Planes with the newer HEPA filters are 99.97% effective at trapping particles down to a size of .3 micron, according to the American Society of Heating, Refrigerating and Air-Conditioning Engineers, which has been involved in studying standards for airplane air circulation.

To avoid the allergens in the air or on seatmates, travelers who are sensitive should ask their doctor’s advice before the trip. A non-sedating antihistamine such as Claritin, Allegra or Zyrtec, all available by prescription, can help, Spector says.

Other options include a bronchodilator to ease breathing and an asthma preventive drug.

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The Healthy Traveler column appears twice a month.