Miliary Eczema in Cats


Dr Mc Blog

May 27, 2015
My mother has complained of a dearth of articles about cats. Here you are, Mom. The domestic feline or house cat is believed to have appeared as a companion as early as 7,000 or more years BC. Whether part of ancient religions or welcomed as a mouse catcher, the cat was also made to be a pet. Although today many argue the value of a cat compared to a dog, statistics indicate that there are as many, or more pet cats in the world as dogs.

Cats are athletic, inquisitive, intelligent and independent.

One such special cat was Alfred. A sleek golden orange tabby, he had grown into a magnificent 12 pound, well-muscled  cat. Alfred ran his house, assuring punctual meals with scheduled outdoor exercise and afternoon naps in between.  He was about three years old when his owner noticed that his coat was looking a little patchy, and when she picked him up to pet him she felt tiny scabs over his back. Alfred seemed a little irritable when she tried to pet him, squirming away as if his skin hurt. This would not do, so off Alfred and owner went to the vet!

Close examination revealed that Alfred had scratched at himself, evidence of itchy, or pruritic skin. The fine little scabs were clustered close together over his skin, with a few slightly bald patches where he must have scratched off some fur. The working diagnosis for a cat with this kind of skin condition or dermatopathy is called “miliary eczema”. “Miliary” meaning “a rash that resembles tiny seeds” and “eczema” meaning inflamed skin, often itchy or red. This is sort of a catch-all term that describes the rash but not necessarily the underlying cause.

Most often a rash might occur in response to an allergy. But allergy to what? In Alfred’s case his owner medicated him monthly with a flea preventative and indeed, there was no evidence of flea “dirt” (blood sucked from an unlucky pet, passed through the flea’s rudimentary digestive system, and deposited in the fur as flea poop) or any live fleas on the cat. Flea allergies are the most common cause of miliary eczema in cats. Other possible sources of allergens might include contact allergens, something the cat might walk on or roll in, or airborne pollens.

Diet might be another cause of allergies.

Since “miliary eczema” defines only the appearance of the rash, other clues to its cause may be found by noting where the rash occurs on the body. For example, if a rash has broken out near the ears, your vet may look for ear mites. Both bacterial and fungal skin infections may cause similar looking rashes. After questions about your cat’s environment, in particular about any changes or recent introductions to your home or yard, your veterinarian will try to pinpoint a precise cause. Sometimes a skin biopsy is recommended for definitive diagnosis. In some instances the underlying cause is never fully understood.

In Alfred’s case the rash appeared to be a response to an unknown allergen and a trial medication with an injectable steroid was administered. This kind of steroid is a glucocorticoid, not the anabolic steroids infamously abused by some athletes. Cats are somewhat unique here, being resistant to the effects that steroids have on dogs (and people) – they suffer far fewer side effects such as hunger and thirst, as a general rule, but they also respond less well to steroid medications in general. Most cats require injectable medication rather than oral steroid medication for allergies.

Alfred was most gracious about receiving an injection in his derriere and went home to convalesce. Overnight his owner reported that he seemed more comfortable, less restless. By day three Alfred was no longer over-grooming himself (it had crept up so slowly she hadn’t noticed his frantic licking increasing) and was eating at a leisurely pace, not jumping about as if suddenly pricked by something. Within the week the little scabs began to dry up and melt away, leaving smooth skin underneath. By the second week it was clear his fur was growing back in. Alfred was once again a gorgeous golden mini panther!

Alfred was lucky. As the effects of the medication wore off around week six there was no sign of recurrence of the rash. For many cats, if the owner is diligent about flea control their cat will remain clear skinned. For others, a combination of injectable or oral medication may be necessary year round to keep their cat comfortable.

Christine B. McFadden, DVM
Valley Animal Hospital, Merced

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.