Skin allergies (atopic dermatitis) in cats

Photo of black cat on white background


Atopic dermatitis (atopy) is a skin problem caused by an allergy to something in the environment (such as pollen, moulds, grass or dust mite).

Cats with atopy tend to have extremely itchy skin that is usually worst on the head, neck, sides, tummy, armpits and inner thighs. Constant scratching, licking and biting makes their skin red, sore and open to infection.

Atopy is an uncommon condition in cats so your vet will want to rule out common causes of itchy skin before diagnosing it.

Treatment for atopy often includes a special diet, medication to stop the itch and skin supplements. Without treatment, atopy can severely affect a cat’s quality of life but with proper treatment, cats with atopy can live a long, happy life.

What is atopy?

Atopy is a skin condition caused by an allergy to something in the environment, such as tree and grass pollens, moulds and dust mites.

Atopy is an uncommon condition in cats so your vet will want to rule out common causes of itchy skin before diagnosing it.

Fleas, flea allergies and food allergies all cause almost identical symptoms to atopic dermatitis.

Atopy can develop at any age and in any breed of cat, although it’s more common in certain breeds such as the Abyssinian and Devon Rex.

Symptoms of atopy

What is my cat allergic to?

Your vet will want to rule out food allergies, flea allergies and other skin diseases before diagnosing your cat with atopy. If your cat turns out to be allergic to food or fleas this is generally much easier to treat than an allergy to something in the environment.

If your cat is allergic to something in the environment, common triggers include pollen, trees, moulds, dust mites, grass and cleaning products... the list goes on!

There are blood tests available to identify what your cat is allergic to, but they don’t always give accurate results. Your vet may be able to offer or refer your cat for skin testing. Skin tests for allergies tend to be more reliable than blood tests.

It can be helpful to find out what your cat is allergic to. However, it’s not easy and doesn’t often change the treatment they need. Speak to your vet about the pros and cons of allergy testing.

It’s possible your cat may be allergic to more than one thing i.e. food as well as something in environment.


If your cat has atopy, they will need lifelong management. There are three main ways to treat it:

Medical treatment

  • The aim of medical treatment is to control the symptoms, not cure the allergy.
  • Your vet may recommend:
    • Steroids and/or other ‘anti-itch’ medication. These will help stop the itch, make your cat feel more comfortable and allow their irritated skin to heal. There are a few different drugs available. They vary in how effective they are, how often they need to be given, their cost and side effects. Speak to your vet for more information.
    • Antibiotics. Antibiotics aren’t always necessary but may be used if your cat has a skin infection.
    • Ear drops. To treat ear infections.


  • If your cat has had skin and/or blood testing and you know what they are allergic to, tailored vaccines (also called immunotherapy) can be made to reduce the allergic reaction they have to their triggers.
  • The vaccines will need to be given very regularly throughout your cat’s life and work slowly over time. Your cat may take many weeks or even months to show improvement.
  • Immunotherapy doesn’t work for every cat and medication is often still needed to reduce symptoms.

Avoid allergy triggers

  • In an ideal world, we would treat atopic dermatitis by completely avoiding your cat’s allergy triggers which would stop symptoms from developing.
  • Unfortunately, avoiding triggers is almost impossible if your cat is allergic to something in the environment. However, there are some sensible precautions you can take to ensure you cat develops as few symptoms as possible. Check out our ‘Ongoing care’ section below for more information.

Ongoing care at home

Avoid your cat’s triggers

  • The ideal treatment is to avoid what your cat is allergic to so that symptoms don’t have a chance to develop. This is rarely possible for cats with atopic dermatitis because their triggers are in the environment, all around them. You can help reduce the chance of a flare-up by taking precautions such as:
    • Avoid letting them outside when the pollen count is high
    • Avoid sprays in the home (except flea sprays)
    • Vacuum and dust regularly
    • Keep your cat up to date with their flea treatment, symptoms will flare-up if fleas bite them.


  • Skin supplements – help some cats but not others. They aim to improve skin health. You can buy skin supplements from your vet practice, pet shops and online.
  • Special food may be recommended to keep your cat’s skin as healthy as possible.

When to contact your vet

Make an appointment with your vet if your cat has itchy skin, or any of the symptoms above. Whatever the cause, itchy skin very rarely goes away in its own and is likely to make your cat sore and miserable.

You know your cat best. If they don’t have the symptoms listed above but you are still concerned it’s always best to contact your vet.


Treatment for atopy can run into thousands of pounds over a cat’s lifetime. Think about insuring your cat as soon as you get them, before any signs of illness start, so you have all the support you need to care for them.

It’s also very important to speak openly to your vet about your finances, the cost of treatment, as well as what you think is right for your cat. There are often several treatment options so if one doesn’t work for you and your pet then your vet may be able to offer another.


Having constantly itchy, sore skin can make a cat very miserable. However, your cat is likely to live a long and happy life if you work closely with your vet to make sure they get the correct treatment.

Your cat is likely to have ‘flare-ups’ from time to time even after they appear to have been controlled with medication. These flare-ups can be quickly resolved by visiting your vet for treatment.

Published: July 2019

PetWise Pet Health Hub – brought to you thanks to support from players of People’s Postcode Lottery 

Written by vets and vet nurses. This advice is for UK pets only.

Illustrations by Samantha Elmhurst