When was the last time a stranger restored your faith in human nature? For me, it was last Saturday.
My first patient of the afternoon was a cat in a box carried by a woman wearing dangerously high stiletto heels and a slick business suit. The woman turned out not to be the cat’s caretaker but instead a real estate agent. She’d been showing a property to a prospective purchaser when she spotted that the house cat had angry-looking sores and scabs on her head, and she felt duty bound to seek help. She phoned the homeowner (who was away) and got his permission.
The real estate agent did this in the middle of a busy working day, interrupting her own appointments to do so. And she wasn’t even a cat person! What a good Samaritan.
What Causes Scabby Skin?
Scabby skin on a cat is just a symptom. It’s important to find out what’s causing the problem so the underlying issue can be treated. Only then can the scabs resolve.
Take, for example, a cat with an allergy to flea bites. Yes, steroids will improve the scabby skin, but as soon as the steroid wears off, the scabs return if you don’t kill the fleas.
Although flea allergic dermatitis is extremely common, it was not the cause in this cat because of a previous episode involving a scabby head. The cat was getting monthly flea drops.
So what else can cause scabbiness? Let’s look at a list of possible problems.
- Flea allergic dermatitis (FAD): An allergy to flea saliva causes the skin to react and form tiny pinhead scabs that makes the skin feel gritty when you stroke the cat.
- Mosquito bite hypersensitivity: This has a similar mechanism to FAD, but the saliva causing the hypersensitivity comes from mosquitoes, not fleas.
- Ear mites: These tiny mites live in the ear canal, where they scurry around feeding off skin cells and debris. They are incredibly itchy, and the cat is liable to scratch, causing self-harm scabs to the head in the process.
- Ringworm: The fungi causing ringworm are highly infectious. Ringworm causes scaling, scabs and hair loss, most commonly on toes, noses and ears, but it can affect any part of the body.
- Bacterial: Any scratch or bite to the skin can allow bacteria to breach the skin’s defenses and set up infections that result in scabs.
- Cowpox: An unpleasant virus, especially if an immunosuppressed cat picks up infection, which can result in some unsightly scabs.
- Feline acne: Bizarrely, this tends to occur in older cats (rather than the cat equivalent of teenagers) and causes gritty scabs under the chin and around the lips.
- Rodents ulcers/eosinophilic dermatitis: The body mounts an inappropriate immune attack and floods the skin with a kind of white cell called an eosinophil. This causes plaques, ulcers and scabs.
- Food allergy: The cat reacts to a protein in the diet that causes an allergic reaction in the skin. While some cats with food allergy present with upset tummies, a lot more come in with sore, inflamed skin and generalized scabs.
- Pemphigus: In this autoimmune condition, the cat’s immune system targets the skin itself, causing it to flake away, leaving sores that then scab over. This is typically found at the junctions where mucous membranes (such as the lips or anus) meet normal skin.
- Reaction to medication: Certain medicines can cause the skin to erupt into angry sores and scabs. The most notorious for this are some of the drugs used to treat overactive thyroid glands. Happily, stopping that particular tablet is usually enough to resolve the problem.
- Squamous cell carcinoma: This is a form of skin cancer that can cause scabbing in the early stages. This is most common on extremities such as the ear tips or the nose of white cats.
The Good Samaritan’s Cat
A sweet-natured black cat, she didn’t seem in the least put out that her afternoon snooze had been interrupted by a perfect stranger taking her to the veterinarian. She had some dramatic-looking scabs on both temples. She was treated regularly with an effective product that kills both fleas and ear mites, so parasites were less likely.
The cat wasn’t on medication, which ruled out an adverse drug reaction. The size and distribution of the scabs weren’t right for ringworm or cowpox, either. However, she’d had previous flare-ups that had improved with steroid treatment but relapsed once treatment finished.
My strong suspicion was that she has a food allergy, but only time and 12 weeks on a hypoallergenic diet can tell for sure.
This pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed Oct. 11, 2018.