Miliary Dermatitis in Cats: Symptoms and Treatment

It took almost two years after joining our household for the nervous Maine Coon cat to let me touch her. I could only brush against her fur when she decided to approach. My joy was short-lived when my fingers felt rows of small, crusty bumps on her neck. To a rescue volunteer, they were familiar to the touch, signs of miliary dermatitis in cats.

What is Miliary Dermatitis?

It's an umbrella term for any skin condition in cats that results small bumps most often caused by an allergic reaction, according to WebVet. The most common allergies are to fleas, Cheyletiella mites, certain pollens and ingredients in food. Those linked to mites cause a flaking resembling dandruff, though not the same thing.

Peteducation.com cites bacterial, yeast or fungal infections as potential causes. Some cats develop skin infections from lice or are hypersensitive to intestinal parasites. Other causes include hormonal abnormalities, autoimmune diseases and certain nutritional disorders or deficiencies.

What Are the Signs and Symptoms?

The most noticeable signs of miliary dermatitis are multiple small, crusty bumps with red skin underneath them. Usually confined to small areas such as the head or the base of the tail, they can sometimes cover large portions of a cat's body. The disorder takes its name from the size and shape of the bumps, which resemble millet seeds.

Many cats continually itch and lick their skin for relief. This can cause additional damage.

Diagnosis

Veterinarians usually find it easy to diagnose miliary dermatitis simply by examining a cat. The difficulty is finding the precise cause of the condition. In some cats, the location gives hints. For example, lesions clustered around a cat's head are often associated with mites.

Diagnosis involves a complete physical - sometimes very difficult if animal is a feral cat, hates being touched or is extremely nervous - plus a history if one is available. Since the most common cause is fleas, the vet will use a flea comb to look for the insects or flea dirt (feces).

The vet might also take a skin scraping and/or press some clear cellophane tape against the cat's skin and check for mites by looking at the results under a microscope. An exam also includes analyzing the cat's stool for intestinal parasites.

If the vet suspects a food allergy, he or she will prescribe a food trial. This can be difficult to complete when it's impossible to segregate multiple cats in the household at feeding times.

If all these steps fail to pinpoint the exact cause of miliary dermatitis, antibiotics, steroids or a combination of both can reveal if the cat is suffering from an allergy or a bacterial infection. Sometimes it's eventually necessary to perform a skin biopsy.

Types of Treatment

The appropriate treatment for a cat suffering from miliary dermatitis depends on its cause. If the cat is taking a medication for another condition, the vet will temporarily discontinue it if possible to see if it might be the cause.

Products containing pyrethrin can treat fleas, lice and some types of mites. Some mites respond to special dips and injections. The environment also needs to be simultaneously treated by diligent vacuuming, cleaning and sometimes discarding furnishings. In some cases, it might be helpful to use two cycles of chemical "bombs" after temporarily vacating the home each time.

When the cause if ringworm, oral and topical medications with a fungicide are available. The home environment would also require treatment. The appropriate medication can eradicate intestinal parasites causing the cat's miliary dermatitis.

In the case of a bacteria or yeast infection, vets can prescribe antibiotics, antifungal medications and special shampoos. For an autoimmune disorder or allergies, the typical treatment is a tapering dose of steroids plus a potential combination of antihistamines, fatty acid supplements, baths or sprays. Sometimes the problem is so severe that the cat must undergo allergy testing followed by injections for desensitization.

If food is the culprit responsible for the cat's miliary dermatitis, the vet will prescribe a new diet. Owners need to make sure their pet remains on this diet for the remainder of his or her life.

Sources:

http://www.webvet.com/main/article?id=144&med=1

http://www.peteducation.com/article.cfm?c=1+1332&aid=150