What Is Cat Allergy?

If you have opened this article, it is likely that you want to know more about allergies to cats. If that is true, then this piece of writing will hopefully provide a clear understanding of what cat allergies are, establish the effect that these allergies can bear on people, and explain the treatment and remedies that are available to ease this type of allergy.

Definition of a cat allergy

An allergy is a type of inflammatory disease. 1 An allergic reaction occurs when your immune system responds defensively against substances that are typically believed to be “harmless”. These substances that cause allergic reactions are referred to as allergens; common examples of allergens include dust, pollen and animal fur.


Cat allergies are relatively common, especially as cats are a globally popular choice for household pets. In a 2023 review of pet populations in the United Kingdom (UK), it is estimated that there are 11 million domestic cats (felis domesticus) which accounts for approximately 26% of UK households. In America, approximately 25% of households own a cat.2,3

Globally it is estimated that 10-20% of humans are allergic to cats, and this is an increasing figure.4 Cat allergy is the third most common cause of human respiratory allergies, and second most common indoor cause.5,6

Understanding allergies

In order to understand how allergies form and the role of the immune system in this process, it is important to know what our immune system sets out to do.

Our immune system’s primary role is to protect our body from bacteria, viruses and parasites. The immune system produces specific proteins called antibodies (immunoglobulins) to neutralise and eliminate foreign substances (antigens) that it encounters.7 Therefore, allergies occur when the immune system mistakes a harmless substance as a threat.

The most common type of antibody involved in allergies is immunoglobulin E (lgE). When a person with allergies is exposed to an allergen (whether by inhaling or physical contact), their immune system may produce lgE antibodies specific to that allergen.8 Then, when you’re exposed to that same allergen again, these antibodies can release a variety of chemicals (such as histamine) that cause allergy symptoms.

Some people are at a higher risk of developing allergies than others. For example, you are more likely to develop an allergy if: you are a child, one of your parents has an allergy, and/or you have asthma.

Cat allergens

To date, there are eight cat allergens which humans are sensitive to that the World Health Organisation (WHO) has identified.9 These are dubbed Fel d 1 to Fel d 8 by the WHO and International Union of Immunological Societies (IUIS).8

Felis domesticus allergen 1 (Fel d 1) – known as a glycoprotein – is the cat allergen that is the most researched. Fel d 1 is produced by cat saliva and skin glands.10 For several years, allergies to cats have been recognised as a risk factor for the development of asthma and allergic rhinitis.11

And indeed, fel d 1 is considered the primary culprit of allergic rhinitis. It can stimulate hypersensitivities in humans when inhaled or ingested.12,13 The concentration of allergens present in a household depends on the number of cats that live there.14,15

This specific allergy occurs when a person’s immune system overreacts to the proteins found in a cat’s saliva, urine or dander (flakes of skin in an animal’s fur or hair). This then leads to various symptoms.

This type of allergies can bear problematic effects on people’s quality of life, particularly as studies claim that exposure to these allergens is very hard to avoid. This is because dander from cat hair and dried saliva spreads as small airborne particles into the environment, attaching to surface areas such as walls, carpets and furniture. It is thereafter possible for this allergen to adhere to clothes and shoes, and be carried into public spaces where it can persist for months or even years.14,16

Signs and symptoms

Cat allergies can produce a range of symptoms which can vary in severity from person to person. Here is a list of common symptoms of cat allergies:5

  • Sneezing
  • Runny nose
  • Nasal congestion
  • Coughing
  • Watery eyes
  • Itchy eyes
  • Redness of the eyes
  • Skin rash
  • Itchy skin
  • Wheezing
  • Shortness of breath
  • Chest tightness
  • Fatigue
  • Headache
  • Sore throat


If you have a belief or concerns that you are suffering from the symptoms of allergy, your healthcare provider may conduct some allergy tests or refer you to a specialist allergy clinic for this. Tests you may have include:

Skin prick test (SPT)A small quantity of cat allergen extract is applied to the skin, followed by a needle prick which allows the allergen to insert into the skin. If you are allergic, you should see a reaction in your skin within approximately 20 minutes.
Intradermal testA small amount of diluted cat allergen is injected under the skin (usually of the arm); similar to the SPT, an allergic reaction will appear at the injection site.
Blood testsThis method measures the specific amount of antibodies called. immunoglobulin E in your blood.

Treatment and management

There are available non-prescription (over-the-counter) remedies and treatments to help alleviate the symptoms of allergies, however they may not provide complete relief (especially if your allergies are severe). It’s advised to consult with a healthcare professional for proper guidance on seeking treatment. Treatments for allergy symptoms include:

Antihistamines are often used to treat the symptoms of allergy. They operate by blocking the effects of histamine which causes itching.

Decongestants can help by relieving nasal congestion and the ‘stuffiness’ that is associated with allergies. They are available in both the forms of oral tablets and nasal sprays.

Emergency medications such as Epinephrine should be used in the event of a severe allergic reaction. Epinephrine can assist in quickly reversing life-threatening symptoms. It is possible you would have been prescribed an Epinephrine auto-injector (e.g. EpiPen) if you have a history of severe allergic reactions (anaphylaxis).  

Allergy eye drops may be suggested by your healthcare provider if you have allergic conjunctivitis (itchy, red, and watery eyes) to help alleviate these symptoms.

The classical method to treat allergy is allergen-specific immunotherapy (SIT). SIT aims to gradually increase tolerance to the allergen typically via the administration of several injections of extract derived from the source.17

Adequate control of allergy symptoms cannot be solely achieved by avoiding allergens. Let’s explore some options of how you can manage and reduce allergens:18,19

Finding another home for the cat is not an uncommon choice in order to eliminate allergens, but understandably it is not a decision everybody finds easy to make. You could consider environmental control, whereby you can create cat-free zones at home where your cat is not allowed to go. Ensure that you regularly clean your home, your clothes and wash your hands after you have handled your cat.

To help remove allergens from your home, it is advised to use mechanical washing with detergent to clean your contaminated bedding and clothing. If this is difficult, you can alternately use a tumble dryer.20,21

When to see a doctor

It can be easy to misidentify allergies as a cold due to them sharing similar symptoms (such as sneezing or a runny nose). If your symptoms persist for more than two weeks, it is advised to seek the advice of your General Practitioner (GP) or doctor. Another reason to consult your doctor is if your symptoms are not relieved by over-the-counter allergy medicines. 

Seek emergency help if you experience wheezing or shortness of breath that is rapidly deteriorating, or if you are short of breath despite your minimal activity.

In the case of a severe allergic reaction (anaphylaxis), seek urgent medical help by contacting your local emergency contact number. If you own an epinephrine auto-injector (EpiPen), be sure to read its instructions so you are certain about how to use it in an emergency.  


What are the symptoms of cat allergies?

Common symptoms include: sneezing, runny or stuffy nose, itchy or watery eyes, coughing, wheezing, skin rashes and in some cases  difficulty breathing. Consult a healthcare professional if you have these symptoms  especially if they are persisting  for attention and further support.

Can I develop cat allergies later in life?

Yes. It is possible for people to develop allergies and for allergies to develop over time. This is due to various factors which include genetics and repeated exposure to allergens.

How can I manage cat allergies?

There are strategies you can try at home to reduce allergen exposure. These include: keeping cats out of your bedroom, using air purifiers, and regularly cleaning and vacuuming your home. Additionally, you can look into receiving treatment to relieve your symptoms, be it non-prescription remedies or consulting a healthcare professional for further advice. There are also potential treatments such as allergen immunotherapy.

Is there a way to live with cats despite allergies?

Yes, this is possible. You can try to continue living with cats despite any allergies by:

  • Regularly cleaning your home to minimise allergens
  • Filter the air (air-purifiers)
  • Creating allergen-free zones in your home where cats are not allowed
  • Regularly bathing and grooming your cat to reduce allergenic proteins in their fur
  • After handling your cat, wash your clothes and hands to minimise allergen transfer
  • Allergy medications
  • Having a breed of cat that is hypoallergenic
  • Consulting an allergist for personalised advice and treatment options


Cat allergies are a type of allergic reaction that occurs when your immune system reacts to proteins (allergens) found in a cat’s skin cells, urine and saliva. This type of allergy can cause a variety of symptoms, which include: sneezing, runny/stuffy nose, watery/itchy eyes, skin reactions, and shortness of breath. There are non-prescription allergy remedies available at pharmacies which you can purchase to help ease the symptoms of allergy, such as antihistamines, nasal sprays and decongestants.

It is important to note that cat allergies are not exclusively linked to direct contact with cats. Allergens can spread in the air and adhere to surfaces such as walls, clothing and furniture. However, you can help manage the presence of these allergens by regularly cleaning your house and clothes, maintaining good hand hygiene, and regularly bathing your cat.

If your allergy symptoms worsen or you struggle to manage them, consult your GP or healthcare professional for further advice. They can then recommend appropriate treatment and provide personalised advice.


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This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Catrin Emily Jones

Bachelor of Science - BS, Psychiatric/Mental Health Nurse/Nursing, Swansea University

Cat is a qualified mental health nurse who has worked across multiple sectors, such as hospital wards and in the community. Cat has several years of experience in geriatric nursing, specifically dementia care. She is bilingual and is fluent in both the English and Welsh languages.

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