Did you know your cat can suffer from seasonal allergies, the same as you? Cats can react to the pollen and other triggers of our own annoying spring allergies, however, their symptoms are often different than ours. Seasonal allergies in cats are more likely to produce skin symptoms, rather than what humans experience.
According to PetMD, seasonal allergies in cats tend to show up as atopic dermatitis. Your cat might develop an itchy rash around his head and neck. He might also develop skin eruptions, and you might notice fur loss from excessive licking, grooming and scratching.
Seasonal allergies in cats are hard to diagnose, and it's also very hard to figure out just what's causing your cat's skin problems on your own. If you notice skin issues, you need to take him to the vet to rule out other, potentially serious, skin conditions first. It's not a good idea to assume that skin problems are merely allergies.
If your vet diagnoses allergies, one of the ways to find out what your cat is allergic to is with intradermal testing. This is similar to that wonderful test we humans undergo when an allergist is trying to find out what we're allergic to. Cats are usually put under general anesthesia for these tests. Then your vet or veterinary dermatologist will shave a small patch of fur, mark it with a pen, and inject tiny amounts of potential allergens. After anywhere from 8 to 15 minutes, the vet will evaluate the test.
Since this test has a small rate of false positives, it's generally the best way to figure out what your cat is allergic to.
One of the potential treatments for seasonal allergies in cats is a "vaccine." According to veterinarians at PetPlace, your vet will inject your cat with some of whatever he's allergic to, repeatedly, over a period of time. The goal here is to slowly reduce your cat's reaction to the substances. If that doesn't work, then your vet will probably treat him with steroids.