September 29, 2023

Cat Allergy: Symptoms, Testing and Treatment

woman with runny nose holding a cat

Cat allergy is unfortunately a common issue faced by many of us worldwide. Out of all pets, cats are actually the most common pet allergy. There are also up to twice as many people allergic to cats than to dogs.

But why is that? Well, the allergic reaction occurs when proteins from the cat’s saliva, urine or dander come into contact with our immune system. If this is oversensitised, then it can react aggressively by releasing histamine, as if it was coming under attack.

Despite the prevalence of cat allergies, there are still numerous misconceptions. Let’s dive right in and talk about the symptoms, diagnosis, and practical management options.

Causes of Allergies to Cats

The protein responsible for causing cat allergies in most cases is called Fel d 1. When cats groom themselves, this protein gets spread from their saliva onto their fur. From here, it can become airborne and then settle on both soft or hard surfaces. Or it could also directly come into contact with your own skin or nasal airways for example.

Now, if you are an individual already sensitized to this type of protein, your immune system may react to it, causing an allergic reaction. This type of allergic reaction is called a Type I hypersensitivity reaction. This essentially occurs when the reaction leads to the production of Immunoglobulin E (IgE). These are always antibodies produced following an immediate response by the immune system to an antigen that you are sensitized to.

The next step in this cascade is the release of histamines and other chemicals in the body which lead to the actual symptoms.

Cat Allergy Symptoms

Cat allergy symptoms include:

  • Sneezing and runny or stuffy nose (also known as allergic rhinitis)
  • Red, itchy, and watery eyes (also known as allergic conjunctivitis)
  • Skin rashes or hives (also known as urticaria)
  • Redness of the skin and inflammation of a cat scratch mark

These symptoms usually appear within a few minutes. In other cases, it could take severals hours after coming into contact with a cat.

Those with a past medical history of asthma may also find that exposure to cat allergens exacerbates their asthma symptoms. This could manifest through cough, shortness of breath, blocked nose and an objectively decreased peak flow reading.

Optimal management of cat allergies is therefore essential to maintaining a good quality of life for those affected.

Cat allergy testing

A cat allergy test for humans is usually performed through skin prick testing. This should only be performed by a qualified allergist. The skin prick test needs to be interpreted in context and there are also health risks associated with performing it.

The process involves placing a concentrated extract of cat saliva protein on your skin, and pricking it so it enters your epidermis. Once this happens, the idea is that if you are allergic, your immune system will create a local reaction. The severity of your cat allergy is then determined based on the size of this wheal.

An alternative is to perform a blood test that measures the amount of IgE antibodies to the specific cat protein. This test can be used as an indication of an allergy but is often not diagnostic.

How to test for cat allergy at home?

Although home testing for cat allergy sounds attractive and convenient, I can’t recommend this. The home test kits you can buy are essentially a home IgE test that measures the amount of antibodies in your blood. However, there are many false positive results given by this type of test. This means that the test could tell you that you are allergic, when in fact you are not.

If this happens, you could be unnecessarily avoiding cats. Or even worse, getting rid of your current cat although it’s not what’s causing your allergy symptoms.

The best way to test for a cat allergy at the moment is through a skin prick test. There are no shortcuts, and most of the commercial kits for at-home testing are unhelpful for the reasons mentioned.

Management and Treatment

If you know that you are allergic to cats, there are a few things that you can do. I’ve split these into prevention, symptom control, and even a potential cure!

1. Prevent

Controlling your environment should be the first step in getting your allergy under control.

Trying to avoid cats is easier said than done, especially if you’re a cat lover or have friends and family with cats at home.

Some tips you could follow though, include:

  • Vacuuming frequently with a high-efficiency particulate air (HEPA) filter vacuum. This ensures that the cat dander particles are trapped inside the filter and not released back into the environment.
  • Washing bedding and curtains regularly.
  • Using air purifiers to reduce airborne allergens.

2. Control symptoms with medication

There is a wide range of very effective over the counter (OTC) medication for allergy symptom control. The best medication depends on what affects you the most.

You could try nasal steroid sprays if you have allergic rhinitis mostly. There is a wide range of options such as Beconase and Flixonase, which you don’t need a prescription for. There are also more advance formulations such as Dymista which contain a combination of steroid and anti-histamine in spray form.

If you are getting watery, red eyes and other symptoms of allergic conjunctivitis, you could try Optrex allergy eye drops. These contain Sodium Cromoglicate (2% w/v) which can work quite well.

For a systemic anti-allergic effect, try OTC antihistamines such as Cetirizine, Loratadine or Fexofenadine. These are all non-sedating and generally effective in symptoms relief up to a point.

What is the best antihistamine for cat allergy in the UK?

The two antihistamines I tend to recommend are Cetirizine and Fexofenadine.

Fexofenadine has recently come off patent and can now be purchased over the counter as well. It’s a new generation antihistamine that tends to least the longest.

3. Cure

Immunotherapy is an option to many known allergies such as to hay fever and wasp stings. For cat allergies, immunotherapy is still in the experimental phase. While immunotherapy is an option, not everyone sees positive effects.

Just last year, researchers in the USA developed a new monoclonal antibody that has the potential to cure cat allergies. Initial studies showed that these immunotherapy injections led to effective relief from cat allergies even a year after the initial treatment. Currently, though, more research is needed before immunotherapy to cats can be available mainstream.

Hypoallergenic Cats

I sometimes get asked the question on whether there are specific breeds of cats that are more hypoallergenic than others. I feel that this is a common misconception, as cat dander is released by all the cat breeds. Some breeds however are known to produce fewer allergens.

Here is a table with some cat breeds that are thought to produce the least allergens. These may be more suitable for cat lovers with mild cat allergies.

Cat Breed Explanation
Siberian Despite their long fur, Siberians were found to produce fewer allergens due to lower Fel d 1 protein levels.
Balinese Similar to Siberians, they also have lower Fel d 1 allergen levels despite their long fur.
Bengal Bengals have fine fur that requires less grooming. This means there’s less dander spread into the environment.
Burmese Known for lower allergen levels, making them suitable for individuals with mild allergies.
Cornish Rex They have less fur which results in fewer allergens being spread around.
Devon Rex Similar to Cornish Rex, they have less fur and thus spread fewer allergens.
Siamese Known to produce lower levels of allergens compared to other breeds.
Russian Blue Their plush, short coat produces fewer allergens.
Oriental Shorthair Known for lower allergen levels due to their short, fine fur.


Cat allergies can be very problematic when they start affecting your quality of life.

Unfortunately, there is no one-size-fits-all management option when it comes to dealing with them. If you are already known to have an allergy to cats then I hope some of my treatment options mentioned above help. If you’re unsure, get in touch with us and we can organize an allergy test for you if you live in the UK.