Miliary Dermatitis – Skin bumps often caused by allergies

Author: Dr. Beth Turner

Published: April 20, 2015

Updated: December 6, 2021

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itchy cat scratching-Pix

Cats are truly unique creatures. They are masters at hiding issues and when they visit their veterinarian for a problem it feels like Pandora’s box has been opened. Why?

What can seem like a "simple" lesion can actually have multiple causes. This is especially true with cat allergies. The reason being is possibly that cat allergies have not been well defined and research is in its early stages.

The clinical presentation of allergies for cats doesn’t tend to be site-specific as it can be in other species. For example, when a cat starts licking at their belly, it could be due to fleas, food allergies, or atopic dermatitis. Additionally, a furless belly could be due to fleas or to psychogenic causes. Then there are times when some skin issues could be hereditary or idiopathic (no known cause) in addition to being due to allergies. Oh, this tangled web of confusion our kitties weave!

What is Miliary Dermatitis?

Miliary dermatitis is most commonly caused by an allergy to flea bites, but it can also be because of food allergies or atopy (environmental allergies to pollen, mold, dust mites, etc.). And in some cases, it has even been associated with mites, lice, poor diet, infectious diseases, and immune-mediated/autoimmune diseases – these diseases, such as pemphigus foliaceus or FIV, decrease your cat's immune system and affect how they fight diseases and infections.

While the name implies it is a specific type of skin disease, it is more of a disease condition. The term is used when describing a skin condition characterized by a rash that is around the head, neck, and/or body. The name is derived from the Latin word for millet, milium, in order to describe the small crusted lesions that have a millet seed appearance.

Those bumps on your cat's skin

The general appearance of miliary dermatitis is discrete light brown crusts that can be present anywhere on your cat's skin – they can also be evenly distributed over their entire body. Cats will lick, bite or scratch due to the fact that they are mild to intensely itchy – which only makes it worse. There are times that even touching your cat’s skin causes them to scratch, lick, bite, or twitch.

More often than not, the lesions are easier to feel than see. You may notice your cat’s coat thinning over the affected areas. As the condition progresses and becomes more severe, infections can develop resulting in pustules (pimple-like lesions). Resist the urge to pop them!

How is Miliary Dermatitis Diagnosed?

If you notice that your cat is licking, biting, or scratching more than normal or you feel ‘bumpy skin’ when you pet them, it is time to contact your veterinarian.

Your veterinarian will fully examine your cat and make a determination as to the cause of the miliary dermatitis. Identifying the cause is important so that the correct treatment can be provided.

So what things will your veterinarian do to help diagnosis the cause?

  • Figure out the primary location of the lesions. While this isn’t always specific, it can be helpful. For instance, if the lesions are predominately at the base of the tail, fleas are the likely problem. But if the lesions are mostly around the head and neck, mites may be to blame.

  • Analyze samples of your cat’s fur and perform skin scrapings to look for mites, lice, fleas, or other causes of skin infections (like bacteria or yeast).

  • Conduct an intestinal parasite analysis. They obtain a poop sample looking for intestinal parasites (i.e., hookworms, roundworms, tapeworms, etc.).

  • Retrieve a blood sample for a complete blood count (CBC) and chemistry panel in order to determine if there are any undiagnosed medical conditions. Any disease, such as irritable bowel syndrome, mast cell tumors, kidney disease, or hyperthyroidism can make your cat susceptible to allergies and therefore miliary dermatitis.

  • Your veterinarian may need to perform a skin biopsy. They will surgically remove a small area of skin that is infected for analysis.

  • Conduct allergy testing. This can be done with either a blood sample or by skin testing.
bumps on cat skin

How is miliary dermatitis treated?

Allergies to flea bites are the most common cause but the causes can be varied. Treatment protocols are based on the specific cause that has been determined by your veterinarian. But one thing to remember, when one allergy is present, often there can be others. Therefore your cat may need a combination of treatments.

  • If fleas are the cause, an aggressive flea treatment protocol needs to be done for your cat, their environment, and any other pets in your home. This will be a continuous routine done year-round.

  • If your cat is found to have mites, lice, or some other parasite causing the issue, treatment must be done and preventative measures must be put in place. Many flea/tick products can help with treatment and prevention.

  • If intestinal parasites, such as worms are the issue, routine deworming every 3 to 4 months can eliminate and prevent future infections. Several flea products include intestinal worm preventatives.

  • There are times when other causes have been ruled out, that your cat will be started on a food trial. What this means, is that they are started on a hypoallergenic diet and they are not allowed any other food sources for an 8 to 12 week time period. This can help determine what ingredient, usually the protein, that is causing the allergy.

  • Antibiotics may be needed if skin infections have developed because of the excessive licking, scratching, and biting.

  • Shampooing with medicated shampoos (like this antibacterial and antifungal shampoo) can help relieve the itching, inflammation, and bacterial or yeast infection.

  • In some cases, corticosteroids may be necessary for the itching and inflammation.

  • Immunotherapy, based on the results of allergy testing, may be needed. This therapy can be given orally or as a shot. There is an 85 to 90% rate of success in improving allergy symptoms. Typically it will take 3 to 6 months to start seeing some benefits and 12 to 24 months before full benefits are noted. The optimal duration of therapy is still being determined and is unique to each pet.

  • For some cats, antihistamines have been shown to be beneficial. For appropriate dosing for a cat of antihistamines, like Benadryl®, check out our diphenhydramine calculator.

  • Supplements, such as fish oil, can be beneficial, but will likely not cure the condition. However, it can help lessen inflammation in the skin and decrease itching.
Omega 3,6,9 Supplement for Cats and Dogs
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Nordic Naturals Omega 3 Fish Oil Liquid 
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Grizzly Pet Omega 3 Oil Supplement
fish oil supplement for dogs and cats

It is important to follow the treatment that your veterinarian recommends. Failure to comply can cause your cat to have a relapse and prolong the entire recovery process.

Remember, an itchy cat is not a happy cat and if your cat ain’t happy, ain’t nobody happy! So, once the cause is determined, be sure to actively work on preventing it.

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About the author

Profile picture for Dr. Beth Turner

Dr. Beth Turner

Beth Turner is a veterinarian with over 20 years of experience. She graduated from North Carolina State College of Veterinary Medicine and following graduation, she began her career as an associate veterinarian and worked closely with the local shelter.

In 2007 she accomplished her dream of practice ownership, designing and building her own clinic. Another meaningful role, while running her clinic, was serving as her county's shelter veterinarian. This gave her the opportunity to help improve the lives of many animals in her community as well as work with the rescue she loved. She sold her practice in 2019 to move across the country.

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