What causes cat skin allergies

In rare cases, an allergy can lead to a severe allergic reaction, called anaphylaxis or anaphylactic shock, which can be life threatening.

This affects the whole body and usually develops within minutes of exposure to something you’re allergic to.

Signs of anaphylaxis include any of the symptoms above, as well as:

Anaphylaxis is a medical emergency that requires immediate treatment.

Read more about anaphylaxis for information about what to do if it occurs.

Sheet final reviewed: 22 November 2018
Next review due: 22 November 2021

Are You Allergic to Your Pet?

Breathe Easy—You Can Still Hold Your Animal Companion!

Although numerous people own discovered the beneficial effects of caring for a furry friend, the fact remains that roughly 15 to 20% of the population is allergic to animals. The result? Countless pet parents in unhappy, unhealthy situations—and their beloved pets are the cause! Allergen is the medical term for the actual substance that causes an allergic reaction.

What causes cat skin allergies

Touching or inhaling allergens leads to reactions in allergic individuals. Symptoms can include red, itchy, watery eyes and nose; sneezing; coughing; scratchy or sore throat; itchy skin, and most serious of every, difficulty breathing.

The most common pet allergens are proteins found in their dander (scales of ancient skin that are constantly shed by an animal), saliva, urine and sebaceous cells. Any animal can trigger an allergic response, but cats are the most common culprits. People can also become allergic to exotic pets such as ferrets, guinea pigs, birds, rabbits and rodents.

There is no species or breed to which humans cannot develop allergies.

What causes cat skin allergies

Fur length and type will not affect or prevent allergies. Certain pets can be less irritating than others to those who suffer from allergies, but that is strictly on an individual basis and cannot be predicted.

Once the diagnosis of a pet allergy is made, a physician will often recommend eliminating the companion animal from the surroundings. Heartbreaking? Yes. Absolutely necessary? Not always. Hold in mind that most people are allergic to several things besides pets, such as dust mites, molds and pollens, every of which can be found in the home.

Allergic symptoms result from the entire cumulative allergen load. That means that if you eliminate some of the other allergens, you may not own to get rid of your pet. (Conversely, should you decide to remove your pet from your home, this may not immediately solve your problems.) You must also be prepared to invest the time and effort needed to decontaminate your home environment, limit future exposure to allergens and discover a physician who will work with you. Read on for helpful tips:

Improving the Immediate Environment

  1. Dust regularly.

    Wiping below the walls will also cut below on allergens.

  2. Limit fabrics. Allergens collect in rugs, drapes and upholstery, so do your best to limit or eliminate them from your home. If you select to hold some fabrics, steam-clean them regularly. Cotton-covered furniture is the smartest choice, and washable blinds or shades make excellent window treatments. You can also cover your furniture with sheets or blankets which you can remove and wash regularly.
  3. Clean the litter box frequently. Use low-dust, perfume-free filler.

    Clumping litter is a excellent choice.

  4. Install an air purifier fitted with a HEPA filter. Our modern, energy-efficient homes lock in air that is loaded with allergens, so it’s brilliant to let in some unused air daily.
  5. Vacuum frequently using a vacuum equipped with a HEPA (high-efficiency particulate arresting) filter or a disposable electrostatic bag. Other kinds of bags will permit allergens to blow back out of the vacuum.
  6. Use anti-allergen room sprays. These sprays deactivate allergens, rendering them harmless. Enquire your allergist for a product recommendation.
  7. Create an allergen-free room.

    A bedroom is often the best and most practical choice. By preventing your pet from entering this room, you can ensure at least eight hours of liberty from allergens every night. It’s a excellent thought to use hypoallergenic bedding and pillow materials.

  8. Invest in washable pet bedding and cages that can be cleaned often and easily.


Decontaminating Your Pet

  1. Note any symptoms of dermatitis exhibited by your companion animal.

    Dermatitis often leads to accelerated skin and fur shedding, which will up your allergen exposure.

  2. Bathe your pet at least once a week. Your veterinarian can recommend a shampoo that won’t dry out his skin. Bathing works to wash off the allergens that accumulate in an animal’s fur.
  3. Wipe your pet with a product formulated to prevent dander from building up and flaking off into the environment. Enquire your veterinarian to propose one that is safe to use on animals who groom themselves.
  4. Brush or comb your pet frequently. It’s best to do this outdoors, if possible. (The ASPCA does not recommend keeping cats outdoors, so make certain your feline is leashed if you take him outside.)


Taking Care of Yourself

  1. Designate a “pet outfit” from among your most easily washed clothes.

    Wear it when playing or cuddling with your companion, and you’ll leave other clothing uncontaminated.

  2. If possible, own someone other than yourself do the housecleaning, litter box work and pet washing, wiping and brushing. If you must clean the home or change the litter, be certain to wear a dust mask.
  3. Wash your hands after handling your companion animal and before touching your face.

    The areas around your nose and eyes are particularly sensitive to allergens.

  4. Find a physician, preferably an allergy specialist, who will make certain that your pet is the cause of your allergies and will assist alleviate your symptoms. Medications and immunotherapy (desensitizing shots) can often permit you and your companion animal to remain together happily ever after.

Studies own shown that food allergies overall are the third most common type of feline allergy, outranked in frequency only by allergies to flea bites and inhaled substances.

Although itchy, irritating skin problems are the most common signs of this allergy, an estimated 10 percent to 15 percent of affected cats also exhibit gastrointestinal signs, such as vomiting and diarrhea.

The itching that typically signals the presence of a food allergy is caused by the eruption of little, pale, fluid-filled lumps on a cat’s skin, which form in response to the presence of an allergen, a substance to which the animal’s system is abnormally sensitive.

“The itching eruptions primarily affect the head and neck area,” says Carolyn McDaniel, VMD, a lecturer in clinical sciences at Cornell University’s College of Veterinary Medicine.

“They’re not always in that area, but often enough to serve as a clue that the source is a food allergy.”

In themselves, the aggravating lesions do not pose a significant health hazard. But the incessant scratching that they immediate may cause secondary skin wounds and a resulting vulnerability to severe bacterial infection.

What causes cat skin allergies

In addition, gastrointestinal problems stemming from a food allergy may own far-reaching systemic implications, including food avoidance that can result in health-compromising weight loss.

The most visible signs of a food allergy—the persistent scratching, the emergence of skin lesions, loss of hair, and a general deterioration of the coat—do not develop overnight.

What causes cat skin allergies

Instead, they tend to become evident and intensify over extended periods of time—months or even longer—as the animal’s immune system gradually mounts a defense against certain protein and carbohydrate molecules that are present in most standard cat foods. “We don’t know why this allergy develops,” says Dr. McDaniel. “A cat of any age can be affected, and it can happen in a cat that has been on the same diet for years.”

When the signs appear, a cat should get immediate veterinary care. If a food allergy is indeed suspected, the specific allergen should be identified and removed from the animal’s diet.

After other potential causes of the skin eruptions, such as flea bites, are ruled out and a food allergy is identified as the probable cause of the clinical signs, the next challenge is to identify what precisely in the cat’s diet is responsible for the problem.

This process will most effectively be carried out at home by the owner’s introduction of what is termed a “novel” diet, which is based on the fact that most feline food allergies are traceable to the protein or carbohydrate content of an affected animal’s normal fare.

The most commonly used protein sources in cat food include beef, pork, lamb, chicken, turkey, and eggs. Since protein is a fundamental component of living cells and is necessary for the proper functioning of an organism, the novel diet must contain protein—but it must be derived from a source to which an affected cat has not been previously exposed, such as venison or kangaroo meat.

Since the same holds true for carbohydrates, the vegetables that are frequently used in cat foods—wheat, barley, and corn, for instance—would be excluded from the novel diet and replaced by, for example, potato.

If a cat consumes nothing but the novel diet and water for a period of at least eight to 10 weeks, it is likely that the allergic signs will gradually vanish. In that case, the owner can assume that the allergen was a component of the previous diet. And to identify the specific offending allergen, the owner subsequently reintroduces components of the cat’s original diet one by one and watches carefully for the reemergence of allergic symptoms.

If the symptoms recur, they will probably do so within a week or two, in which case the owner will own confirmed at least one source of the allergy.

Through repeated systematic testing—and a lot of patience—it is possible for the owner to pinpoint every dietary ingredients to which a cat is allergic. Therapy, it follows, requires the permanent exclusion of these ingredients from the cat’s diet.

Fleas remain the most common cause of skin disease in cats, although this is not true in every countries (in some regions fleas are rare), and fleas are not the only cause of pruritus (itchy skin) in cats.

Where fleas are not the answer, often a much more detailed and meticulous approach is needed to discover the diagnosis.

In some instances in cats, it can be extremely hard to differentiate between skin disease due to pruritus and skin disease induced by other causes. For example, in humans and dogs, hair loss is almost always hormonal in origin. However, in cats, hormonal skin disease is so rare as to be virtually non-existent. Hair loss in cats is actually almost always caused by excessive self-grooming due to pruritus — but cats may be ‘secret groomers’ and often we may be unaware that the cat is grooming more frequently or more aggressively.

Severe pruritus and eosinophilic 
plaques associated with flea allergy – note matting of the fur with saliva


What can cause cats to itch other than fleas?

Important causes of pruritus other than fleas include:

  1. Insect bites
  2. Atopy (house dust and pollen allergy)
  3. Food intolerance/allergy
  4. Ear mites and other mites
  5. Bacterial infections

Other mites

Harvest mites are a recognised cause of skin disease in cats in some areas in tardy summer and autumn – see harvest mite infection in cats.

These tiny orange dot sized mites are visible to the naked eye and generally found between the toes and in Henry’s pocket of the ear flap.

In some parts of the world, the mites Noedres cati and Sarcoptes scabiei may be found on cats and may be a cause of intense pruritus.

Atopy (atopic dermatitis; dust and pollen allergy)

Atopy is not well characterised in cats. In humans and dogs, the term is strictly used to describe an inherited predisposition to develop allergic reactions to environmental allergens (such as pollen and home dust). Allergies to pollen and home dust happen in cats, and may be a potential cause of pruritus, but they are hard to diagnose and it is unknown whether there is an inherited component to the disease.

In most cats, atopy is diagnosed by ruling out other potential causes of pruritus, including fleas and other parasites, and food.

Allergy testing can be performed on cats (for example intra-derma skin tests) but the results are rather unreliable. Blood tests are also offered by some laboratories to ‘diagnose’ atopy and the underlying cause of the allergy, but these are less dependable than skin tests, and both untrue positive and untrue negative tests are well recognised.

Atopy is incurable and life-long medication is needed to prevent unacceptable discomfort. Treatment with essential fatty acids and anti-histamines is successful in only a minority of cases. Numerous cats need long-term corticosteroids or other immunosuppressive drugs such as cyclosporin.

If an allergy test has successfully identified the offending allergen, then it is possible to use a ‘hyposensitisation vaccine’ as a therapy – these rarely resolve the disease but in some cases reduce the need for drug therapy.

Ear mites – Otodectes cynotis

Ear mites are well known as the major cause of otitis externa (ear inflammation) in young cats and in breeding colonies – see common ear problems in cats. However, it is also possible for the mites to wander onto the skin around the head and neck and cause pruritic skin disease at these sites.

As cats sleep curled up, spread of infection (and subsequent dermatitis) to the rump and tail may also occur.

Insect bites

Insects such as wasps and bees can cause stings that lead to dramatic, painful and swollen skin. However, some other insects including fleas, midges, flies and mosquitoes may bite and the reaction to the bite (or the insect saliva) may cause intense irritation and pruritus. Flying insects generally bite relatively hairless areas such as the bridge of the nose and ears.

Notably, mosquitoes own been reported to cause an eosinophilic granuloma-like reaction on the bridge of the nose of some cats (mosquito-bite hypersensitivity).

Food intolerance or allergy

No-one knows the exact mechanisms by which certain foods can make animals and humans itch. Allergy may be involved, but in some cases, it is possible that the pruritus may result from chemical reactions to the food or to additives and preservatives.

However, it is well recognised that changing the diet to a food that cats own not previously been exposed to can cure some cases of pruritic skin disease.

Most of these are probably food allergies but the terms ‘food intolerance’ or ‘food-responsive’ skin disease are sometimes used as a specific diagnosis is often not made.

Cats may need to be fed an alternative diet for a period of 6-8 weeks to law out food-response dermatitis, and the choice of food is significant. This is not simply switching one brand of cat food for another, as the ingredients are often extremely similar.

What causes cat skin allergies

Your vet will advise you on the most appropriate diet to use – this might be a home-prepared diet, or your vet may propose a special ‘hypoallergenic’ diet for the trial period. Numerous cats also hunt or may be fed by neighbours, which can complicate the trial as it is significant that no other foods are eaten during the trial period.

Bacterial skin infections (pyoderma) and fungal (yeast) infections

Although bacterial skin disease in cats is unusual, it may happen and there are occasional cases of spectacular recovery following antibiotic treatment in pruritic cats. This is unusual, but more work is needed in this area.

Dermatophytosis (infection with a dermatophyte fungal organism) is not generally pruritic, but skin infection with yeasts (Malassezia) can be a problem in some cats – this is often secondary to allergic skin disease, but the yeasts may also contribute to the pruritus.

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Manifestations of feline pruritus

Common manifestations of pruritic skin disease in cats include:

  1. ‘Miliary’ dermatitis – this form of skin disease is characterised by the presence of tiny 2-3 mm diameter crusts throughout the body surface.

    The skin and jacket may also be greasy and own excessive dandruff

  2. Symmetrical hair loss
  3. Overt itching, scratching and self-induced skin damage
  4. Eosinophilic granuloma complicated – see eosinophilic granuloma complicated in cats – this is a variety of skin lesions (indolent ulcer that affects the upper lip, and eosinophilic plagues or eosinophilic granulomas that can affect various areas of the body and also the oral cavity. They are generally associated with allergies.

    What causes cat skin allergies

    Every of these manifestations of pruritus glance completely diverse, but can every be caused by the same things — in most instances the cause is fleas but other parasites and allergies can be involved. Some cats may own more than one manifestation of disease present simultaneously eg, indolent ulcer and symmetrical hair loss.


Main allergy symptoms

Common symptoms of an allergic reaction include:

  1. swollen lips, tongue, eyes or face
  2. a raised, itchy, red rash (hives)
  3. itchy, red, watering eyes (conjunctivitis)
  4. tummy pain, feeling ill, vomiting or diarrhoea
  5. sneezing and an itchy, runny or blocked nose (allergic rhinitis)
  6. wheezing, chest tightness, shortness of breath and a cough
  7. dry, red and cracked skin

The symptoms vary depending on what you’re allergic to and how you come into contact with it.

For example, you may have a runny nose if exposed to pollen, develop a rash if you own a skin allergy, or feel sick if you eat something you’re allergic to.

See your GP if you or your kid might own had an allergic reaction to something. They can assist determine whether the symptoms are caused by an allergy or another condition.

Read more about diagnosing allergies.


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