“Hot spots,” a sudden-onset sticky skin infection, is a much more manageable name for what your vet might tell you is “acute moist dermatitis.”
Hot spots are not as common in cats as they are in dogs. They cause discomfort and soreness; the condition generally develops after scratching that is triggered by another problem such as a parasite infection or an allergy.
Generally, acute moist dermatitis is not serious and is easily cleared with the timely use of medication.
A patch of moist dermatitis looks like an inflamed sticky area on the skin. Frequently, the patch’s hair falls out; the fur surrounding the area becomes sticky and soiled by discharge.
The most common places to get a patch of moist dermatitis are on the head, neck or rump.
Acute moist dermatitis develops when the surface of the skin is damaged by licking or scratching; bacteria then breach the skin’s immunity and set up an infection.
Hot spots are a clue that your cat is itchy for some reason. In addition to treating the infection, you’ll need to take a wider view to find out why your cat scratched himself in the first place.
A hot spot is not difficult to diagnose because of its typical red, sticky and sudden appearance.
The first stop is to check for parasites. This is easily done with coat brushings to check for flea dirt and examining hair samples under the microscope. Sometimes deeper skin scrapes are needed to look for parasites that burrow into the skin.
Another source of irritation is allergies. Food allergies are perhaps more common than we think; there is no reliable lab test for it, so if your vet thinks your cat has a food allergy, she may suggest a trial period on a hypoallergenic diet to see if the symptoms disappear.
Clip the fur away from around the hot spot because the patch is often larger than it appears on first inspection. This also allows air to circulate over the surface of the skin, helping to dry up the infection.
The hot spot should be cleansed with a disinfectant such as diluted chlorhexidine and then patted dry. If the infection is mild, your vet may prescribe a topical antibiotic cream to deliver it locally to the skin. If the infection is more deep-seated, then oral antibiotics for a couple of weeks may be necessary.
The itch-scratch cycle also needs to be stopped to prevent further damage and new flare-ups. To this end, a one-off steroid injection or a short course of oral steroid may be needed.
Treatment of any predisposing factor, such as parasites or allergies, is essential.
This involves good parasite control so flea bites don’t trigger an itch that causes the cat to scratch and damage his skin.
Poor air circulation to the skin can also allow bacteria to build up on the surface. This can happen in a knotted or thick coat; consider getting a long-coated cat clipped short in the hotter months.
- BSAVA Manual of Canine and Feline Dermatology. Jackson & Marsella. Publisher: BSAVA Publications. 3rd edition.
This pet health content was written by a veterinarian.