Skin Allergies & Dermatitis in Cats

There is no doubt about it, skin allergies are frustrating for both pets and their owners, and are one of the most common reasons for bringing a pet to the vet. Skin allergies cause irritation and itching, often resulting in scratching hair loss, skin damage, grazes and bacterial infections. Cats can often lick and overgroom rather than scratching, but the end result is the same.

Allergies are probably the most common cause of itchy skin in cats, however they are not the only cause, so if your pet is itchy or has skin problems it is worthwhile having them fully checked and treated by your vet first.

To get a little technical, an allergic reaction occurs when the immune system responds excessively to a normal substance, such as a pollen, dust mite or spore. This reaction results in the skin becoming irritated and inflamed, which in turn damages the natural protective skin barrier, allowing further irritation and in some cases bacterial infections. This can then set up a vicious cycle of itching and scratching. Unfortunately, the hot and humid climate in Hong Kong may increase the chance of both allergic reactions and secondary infections.

Allergies in cats can often result in really itchy sores, rather then the more widely distributed rashes that we see in dogs (or in people).

There are several types of skin allergy: environmental allergies, food allergies, contact allergies and allergies to insect bites. It’s often difficult to determine the exact type of allergy based on just the signs, but it can be important in helping to eliminate or avoid the cause of the allergy.


Environmental allergies (also called atopy or hayfever) are by far the most common cause of skin irritation in pets, and is due to sensitivity to normal particles called allergens in the air. Common environmental allergens include dust mites, pollens and molds, and signs may often be more common at certain times of the year, such as the start of summer. Allergens are impossible to completely eliminate, even in the cleanest of houses.

Contact allergies tend to affect only the part of the animal that comes in contact with the allergen, often the belly and armpits. Contact allergens may include carpet fibres, washing powders or anything the cat closely touches. Allergens can often be reduced by changing cleaning products or rinsing floors or clothing thoroughly with water.

Insect bite allergies, especially flea bite allergy, can also be a big problem. Some animals can react much more strongly to a flea bite, resulting in intense itching and irritation. For this reason, all cats with itchy skin should be taking flea prevention with a product such as Frontline for Cats.

Lastly, food allergies make up approximately 10-20% of skin allergy cases. Food allergies can cause an upset stomach, loose stools and gastrointestinal irritation, but in many cases the only sign of food allergies is itchy skin, especially around the mouth and feet. Food allergies are often present all year round, unlike environmental allergies, and commonly involve beef, wheat, dairy, egg and chicken. One of the best ways to help with food allergies is to cut out any snacks or treats and monitor the response. This will need to be done for 6-8 weeks in order to give time for the skin to adapt.

Similar to allergies in humans, allergies in pets are difficult to permanently cure. However, with a little care and planning we can greatly reduce allergies and also minimise the use of medication.

When treating skin allergies it is important to approach the problem from all angles, including Limiting Allergen Exposure, Reducing Skin Inflammation and Improving Skin Health.

Please read on for more information on how to help. Limiting Allergen Exposure.