WHAT’S NEW IN CAT ALLERGY?

Are you one of the millions who suffer with cat allergy?

Cat allergy is twice as common as dog allergy and usually associated with severe symptoms of sneezing, nasal itching and congestion and itchy, watery eyes. Cat allergy can trigger asthma, resulting in coughing and wheezing. In some cat-allergic people, a lick from a cat can cause hives.

Most people with cat allergy are allergic to a protein from cats called Fel d 1. This protein is produced in the cat’s skin, tears, saliva and urine and is found on the cat’s hair as the cat licks itself during grooming. We know that male cats produce more Fel d 1 than female cats, and neutered cats produce less than unneutered cats. There are no hypoallergenic cats, as all cats produce some Fel d 1. Another characteristic of Fel d 1, which can lead to severe allergies, is that this protein is very sticky, and it can be transferred on clothing to areas where there are no cats. It’s hard to get rid of Fel d 1 and takes up to four to six months to break down, so it can accumulate over time, creating increasing levels that can cause allergy and asthma flare-ups.

Recently, there has been fascinating new research into the possibility of treating cat allergy by making the cat produce less Fel d 1. Scientists in Switzerland and the United Kingdom reported their work on the development of a vaccine to immunize a cat against their own Fel d 1. The study showed the vaccine made antibodies to neutralize the Fel d 1. More than 50 cats were vaccinated, and they all tolerated the vaccine with no toxic reactions. The researchers showed Fel d 1 levels in the cats’ tears decreased by more than a two-fold factor. Also, a test that measured the allergenic activity of the Fel d 1 in the tears following the vaccination showed it to be reduced compared to before immunization. More studies will need to be performed to show it’s safe for cats over the long term and to determine if levels of Fel d 1 can be lowered enough so people with cat allergy don’t have symptoms.

Another study used a special cat food to reduce levels of Fel d 1 in the cat. This food contained an antibody to bind the Fel d 1 and reduced the amount of the allergenic protein released by the cat. The researchers showed a 47% average decrease in Fel d 1 on the cat’s hair in the 105 cats that were part of the study. The cats tolerated the new food well with no weight loss or toxicity. A separate small pilot study used 11 people with cat allergy who were exposed to blankets on which the cats were fed a regular cat food and the special cat food with antibodies to Fel d 1. When these patients were exposed to the blankets from cats given the special diet, there was a significant decrease in overall nasal symptoms and nasal congestion but not eye symptoms. Further studies are needed to see if this treatment can lead to reduced symptoms in cat allergy sufferers. Nevertheless, it’s great to see these new approaches that hopefully will allow people with cat allergy to have a feline friend.