Sarcoptic Mange (sarcops or scabies) -
Sarcops mites are microscopic and burrow just under the skin. The mite causes severe crusting and is very itchy. Although the mite can burrow anywhere on the body, it populates mostly around the head and ears. Sarcops is diagnosed with a skin scrape that is examined under the microscope. Special dips and injections kill this mite that is contagious to other animals and people, but does not infect the environment. In people, the mite causes severe itching and tiny red bumps.
Miliary Dermatitis -
Miliary dermatitis is a fancy term for tiny red bumps on the skin. Bumps can be all over the body or concentrated in one area, such as around the neck. Miliary dermatitis is caused by inhalant or food allergies which are extremely difficult to diagnose in cats. Diagnosis is often by process of elimination. Treatment options include eliminating potential causes like new bedding, antihistamines, special shampoos or food, or in severe cases, steroids.
Skin Cancer -
Any new lumps or bumps on your cat should be evaluated by your veterinarian. While most skin bumps are benign or not cancerous, your vet may recommend a biopsy to diagnose the type of tumor. Tumors to worry about include those that feel attached to underlying tissue and those with irregular or large margins.
Immune Mediated Problems -
Plaque-like lesions can occur on cats' lips most commonly but can be seen on other areas of the body. This problem is called Eosinophilic Granulomatous Complex and is thought to be an immune-mediated problem with underlying allergies. These lesions need to be biopsied to correctly identify them and treatment includes serial steriod shots. The lesions can resolve completely and then recur in the future.
Since many skin problems can mimic each other, examination and diagnostics should be done by your veterinarian.
