Feline Miliary Dermatitis ~ Pawprints and Purrs, Inc.

Feline Miliary Dermatitis

Miliary dermatitis - also known as papulocrustous dermatitis - is a term that is used to describe the appearance on a cat's skin of multiple crusty lesions. The lesions of feline miliary dermatitis are multiple small, crusty bumps with redness underneath. The lesions are sometimes limited to small areas of the body like the base of the tail, or around the neck or head areas. In other cases, the lesions can cover a large portion of the body. Many times the lesions are itchy, sometimes severely so. In these cases, there may be more severe damage to the skin because of the constant scratching and licking by the cat, which in turn, may bring on grooming disorders. Feline miliary dermatitis has been known as "scabby cat disease", "feline eczema" and "blotch". The word "miliary" is used because the lesions look somewhat like millet seeds.

Feline miliary dermatitis is not really a specific disease itself but a set of symptoms which can be caused by a vast number of diseases. This inflammatory reaction of the skin is common to a wide range of underlying conditions including:

Parasitic infections of the skin (e.g., flea, mite, and lice infestations).
Bacterial infections.
Fungal infections.
Yeast infections.
Autoimmune diseases.
Hypersensitivity skin conditions - allergies, including flea bite hypersensitivity; atopy (such as allergies to pollens); and food hypersensitivity.
Hypersensitivity to intestinal parasites.
Nutritional disorders (biotin or fatty acid deficiencies).
Hormonal abnormalities.
Dermatophytosis (often referred to as "ringworm" which is not a worm but a fungus).

As many as 8 out of 10 cases of miliary dermatitis in cats are thought to be the result of flea bite hypersensitivity, but in some cases no underlying cause is identified.

Miliary dermatitis is an irritating and uncomfortable condition for a cat. In addition, the longer a case is left untreated, the more severe the symptoms will become and the more difficult it may be for your vet to identify the underlying cause. For this reason, all cases should be taken seriously.

Common Symptoms

The crusty lesions may appear in just one small area, or over a large extent of a cat's body in a severe case. The lesions can be felt as tiny lumps in the skin, and the crusts that are produced in association with them may feel as though sugar has been sprinkled in the coat. Other symptoms may include the following:

Skin twitching, due to irritation.
Areas of alopecia (loss of hair) due to the cat's excessive grooming and scratching attempts to relieve irritation; such areas may contain broken, "stubble" hairs.
Other symptoms associated with excessive grooming and nibbling, including vomited hair balls, fur trapped between the teeth, and fur appearing in the cat's feces.
Obvious temperament changes, such as general restlessness and/or aggression when handled.
Some cats also exhibit symptoms of eosinophilic granuloma complex (a group of three different types of skin lesions) at the same time.

All cats are at risk of suffering from miliary dermatitis. If your cat exhibits any of the symptoms described above, have him examined by your vet as soon as possible.

Your vet's aim will be able to identify the underlying cause, in order to be able to prescribe appropriate and specific treatment. The investigations that may be needed will take time, so be patient and do not expect a miracle at your cat's first appointment.

Your vet may be able to prescribe medications that will alleviate the symptoms of this condition in just a few days, but the symptoms will quickly recur if the underlying cause has not be solved.

Sometimes the location of the lesions is helpful. If the lesions are at the base of the tail, fleas are a common cause. If the lesions are around the head, there's a stronger possibility they could be caused by mites. Your veterinarian will give the cat a complete physical and obtain a complete history from you. Your input is very important in attempting to find the cause of the problem.

There may be several stages to the investigation of your cat's symptoms, which may involve:

Physical examination.

Analysis of coat brushings, and of skin and hair samples, to look for dermatophytosis, evidence of fleas and other common skin parasites.

Evaluation of his response to aggressive flea control, both on him and in your home.

Evaluation of his response to a hypoallergenic diet for a period of up to three months.

Intradermal skin tests to check for allergies.

If your vet is able to identify the underlying cause of the miliary dermatitis, he will institute a specific treatment, and if necessary, a prevention regime. Once the cause has been brought under control, the crusty lesions and other symptoms shown should quickly start to resolve. To help speed up recovery if a specific cause has been confirmed, or if the cause remains unidentified despite tests, your vet may resort to a short course of powerful anti-inflammatory medications, such as steriods.

If a cause cannot be identified, repeated courses of medication may be needed as and when symptoms recur, or even on a permanent basis at the lowest dose possible if your cat begins to suffer again as soon as treatment is stopped.

During the period that your cat's symptoms are being investigated, he will still feel uncomforable and possibly irritable. Anxiety, boredom and over-warm conditions appear to make the itchiness worse in many cases, so you should try to ensure that your cat's life is stress-free but interesting, and give him the option of sleeping in a cooler environment than normal if he wishes. You should try to avoid handling and fussing over him unless he is the one to initiate the attention.

You must strictly follow any instructions from your vet about your cat's dietary regime and any flea prevention measures that you should undertake on your cat and in your home.

As flea-bite hypersensitivity is the underlying cause most frequently identified in cases of miliary dermatitis, you should adopt a thorough and well-planned flea prevention from the time that you first bring your cat home to live with you.

Feline Miliary Dermatitis Links for Additional Information:

Allergic & Irritant Contact Dermatitis
Allergies
Feline Miliary Dermatitis
Flea Allergy in Cats
Flea Control in Cats
Food Allergies

Page URL: http://www.sniksnak.com/cathealth/mil-derm.html

Reference Resources:
Cat Doctor, Mark Evans, B Vet Med MRVCS