— Lorraine, New York The information you provide in your question touches upon many important points about cat allergies. First, you describe not having noticeable symptoms with your previous cat but reacting dramatically to the new cat. This is absolutely possible, because cats differ in the amount of allergen they produce. Unfortunately, they don’t differ based upon breed, but rather from individual to individual. First, let me offer a little background about cat allergies. Most people who are allergic to cats are allergic mostly to one protein that is made in the cat’s saliva, sebaceous glands (tiny glands in the skin), and urinary/reproductive tract. This protein is called “Fel d 1.” Individual cats produce Fel d 1 in different amounts, but there are a few generalizations that can be made:
Female cats generally make less Fel d 1 than male cats.Light-colored cats generally make less than dark-colored cats.Long-haired cats may give off less allergen into their environment than short-haired cats, because their long fur holds the protein against the skin better.
So, in theory, a female, light-colored, long-haired cat might be less allergenic. However, all these generalizations may be overridden by a specific cat that just makes a lot of the protein, so they are not actually that helpful. You should also know that Fel d 1 is incredibly lightweight and sticky, so it remains suspended in the air for a long while and then settles and clings to everything: carpets, walls, furniture, clothing, draperies. Cat allergens are “stickier” than just about any other type of allergen. Once a cat is in a home, a “reservoir” of allergen quickly develops in and on the furnishings, and as you move about the house, the allergen gets stirred up and airborne again. In homes with cats, there is a relatively stable amount of allergen around all the time, constantly replenished by the reservoir in the environment, as well as by the cat. Allergy researchers have done studies to look at the impact of washing cats and it is, unfortunately, almost negligible. The levels of Fel d 1 are back up to prebath levels in the air surrounding the cat within 24 hours! The allergen is probably coming both from the cat and from the reservoir, so bathing cats is not worth the effort. There is another possible explanation for what happened to you, Lorraine. Sometimes, when people have lived with an allergen for many years (i.e., your previous cat), they become partially tolerant to that particular animal. This doesn’t happen to everyone, but it can occur. Then, when there is an interruption in the constant exposure to that allergen, followed by a re-exposure, the reaction is stronger. This happens to young people who go off to college and then come back to visit their parents and pets, and suddenly find that they are allergic to something in the home environment in which they grew up. Again, the reasons for this are not entirely clear, but it is a well-known phenomenon. Putting this all together, my advice would be to consider the following options: Good luck, Lorraine! Q2. We just got a kitten in our house and my daughter has been coughing, has a runny nose, and says her chest is hurting. Could she have a cat allergy? The time frame is certainly suspicious with the addition of a new pet and the onset of allergy symptoms at the same time. It seems likely that the kitten is causing your daughter’s symptoms. Why not find out for sure with allergy testing? An immediate skin test at an allergist’s office is in order. If she is allergic to the cat, removal of the animal is the best treatment. However, it’s important to understand that animal dander can linger on for months, even after the pet has gone. So it would be prudent to treat your daughter with an antihistamine minimally and possibly an inhaler as well. Keeping an allergic person in an allergen-filled environment could result in asthma! Q3. What are the breeds of dander-free cats, and are these new “aller-cats” living up to their claims? — Kristen, California Let me preempt my answer by saying that I do not endorse or have any financial interests in any allergy products. That said, Allerca is a company in California that sells hypoallergenic cats. For some years, several companies have been trying to create genetically modified cats that will not cause symptoms in allergic people. The approach was to change the gene (the bit of DNA) that carries the code for a protein called Fel d 1, the protein that causes most people’s cat allergy. However, for reasons that the companies do not disclose, this approach has not proved to be successful. Most likely, the animals were not healthy without the protein. Allerca says on their Web site that they developed hypoallergenic cats in a different manner. They screened thousands of cats to find a few that were naturally lacking Fel d 1 and then bred those animals to develop a line of cats with very low levels of the problematic protein. Perhaps these cats have developed some other ways to make up for the absence of Fel d 1. Apparently, the company will not let outside sources measure the protein levels or do other testing to verify their claims, although my understanding from colleagues is that they did allow an independent allergy researcher to expose allergic patients to the cats in a testing environment and that the patients had no symptoms with short-term exposure. Allerca claims that the cats are very low in Fel d 1, although they are not claiming the animals lack it altogether. Presumably, the levels are low enough that most cat-allergic people do not react. I do not know how many cat-allergic patients the company has tested or how long the people were exposed to the cats. Therefore, based on the available information — again, very little of which is confirmed by independent researchers — the cats appear to be hypoallergenic. The potential problems that I can think of with this approach are the following: However, even with these potential problems in mind, if you have cat allergies and really want a cat, do not think that $4,000 is too costly, and don’t object to promoting the breeding of cats when the nation’s animal shelters are already full of unwanted cats, then yes, I think these animals might be worth a try. So far, the only information available indicates that these cats are what they claim to be. Learn more in the Everyday Health Allergy Center.
