This skin disease is caused by an allergic skin reaction to a number of
possible allergens, including the bites of fleas, mosquitoes, mites, and
lice. Bacterial and fungal skin infections, nutritional disturbances, hormonal
imbalances, autoimmune diseases, and drug reactions can also produce miliary
dermatitis. The affected cat breaks out along her back
and around the head and neck with small bumps and crusts about the size
of millet seeds beneath the haircoat. There may or may not be itching.
Flea bite allergy is the most common
cause of miliary dermatitis in cats.
Other skin parasites, allergies, and infections should be considered for cats
who have miliary dermatitis without fleas.
The veterinary community has divided vaccines into two main categories, with a smaller third
category. Core vaccines are vaccines that every cat should have at some time
in his life. Noncore vaccines are vaccines that only some cats need, depending
on factors such as geographic location and lifestyle. Other vaccines are also
available but are generally not recommended for any cats.
The typical appearance of a cat with flea-bite dermatitis: small crusts,
bumps, and raw patches of skin, and hair loss due to licking and
The skin is severely itchy and may break down, producing raw patches that
become infected from intense scratching. Localized or generalized eosinophilic
plaques may develop as a consequence. A few cats are especially resistant to
flea bites and can harbor many fleas without symptoms, but in the allergic
reactor a single bite once
or twice a week is sufficient to produce the response. Symptoms are most
prevalent in the middle of summer (peak flea season). However, once the cat is
exposed, if fleas live in the house, itching may persist year-round.
The diagnosis is suspected by seeing the characteristic skin rash and by
finding fleas on the cat. You can check for fleas by standing your cat over a
sheet of white paper and brushing her coat. White and black grains of sandy
material that drop on the paper are flea eggs and feces. The diagnosis is
confirmed by an intradermal skin test. This is a hypersensitivity reaction of
both immediate and delayed type; itching tends to persist long after fleas have
Treatment: When fleas are present, treat the infestation. In the absence of
fleas, an effort must be made to determine the cause of the miliary dermatitis
and to treat accordingly.
While treating for the fleas, cortisone tablets, such as prednisone, or
injections that block the allergic reaction and relieve the itching are
sometimes needed to make the cat comfortable. Steroids should only be given
under veterinary guidance. Antihistamines and omega-3 fatty acids may also help
to reduce the inflammation. Treat sores with a topical antibiotic/steroid
ointment. Aloe ointments or an aloe plant’s juice are also soothing and
safe. If the cause of the allergy can be determined and eliminated from
the cat’s environment, such as removing all feather pillows, that would be
ideal. However, this is not always possible. Hyposensitization (using
injections of flea allergens of increasing strength to desensitize a cat’s
immune system) can make cats much more comfortable but requires multiple,
WebMD Veterinary Reference from "Cat Owner's Home Veterinary Handbook"