Vesiculopustular Dermatoses in Cats

A raised bump on your cat can be a worrisome occurrence. Your cat’s skin may be slightly stretched, red or featuring lost patches of hair. Your cat may or may not be irritated by the bumps on the skin. These bumps are called broadly, vesiculopustular dermatoses, a complicated mouthful of a term that refers to serum filled blisters and pus filled bumps in various areas over your cat’s body. Let’s break down the facts about vesiculopustular dermatoses so you know whether to be concerned the next time this condition arises in your pet.

There are two main types of Vesiculopustular Dermatoses in cats. Vesicles, or blisters, are filled with serum, a light or clear colored liquid while pustules are filled with dead blood cells and debris called pus. Here we break the down the symptoms of each of these versions of vesiculopustular dermatoses.

• Small raised bumps in the outer layers of skin
• Bumps can be filled with either serum (vesicles) or pus (pustules)
• Bumps may be reddened
• Alternatively, bumps may be lighter in color
• You cat may scratch or otherwise show irritation around the bumps

Given the different types and varying symptoms, vesiculopustular dermatoses can be brought about by a wide variety of causes. While many times the exact trigger of vesiculopustular dermatoses are unknown, there are some underlying diseases that may lead to the condition.

• Autoimmune disease
• Various forms of lupus
• Dermatomyositis
• Skin infections
• Fungal infection
• Demodectic mange
• Acne
• Skin cancer
• Certain inherited or genetic conditions 
• Allergic reactions to medication

Given the wide array of potential causes of vesiculopustular dermatoses, it will be important to seek medical advice from an experienced veterinarian for proper diagnosis. Many of the underlying causes of vesiculopustular dermatoses can be dangerous to your cat’s life if not identified quickly.

Your vet will typically begin any diagnosis of vesiculopustular dermatoses with a skin scraping of the affected area. The skin scraping will either be examined in your veterinarian’s office or sent to an external specialized laboratory, depending on the nature of the blisters or pustules. Your vet may also choose to lance, or drain, the affected area and collect the fluid for analysis. Finally, your vet will want to take bloodwork to rule out cancer or autoimmune diseases.

All of this will be in connection with a thorough physical exam of your cat. You should also supply your vet with a complete medical history, if known, of your pet. In preparation of the appointment, you should document the affected areas of skin, including noting the time frame when the blisters first appeared, any change in color or size and any medications or changes in food or other living conditions.

Treatment options for vesiculopustular dermatoses in your cat will vary, depending on the underlying cause. Given the wide range of potential causes of blisters or pustules, treatment is likely to be highly tailored to your cat’s specific situation. Here are a few more common courses of treatment. 

Treatment of Acne, Bacterial or Fungal Infection

For the treatment of acne or certain skin infections, your veterinarian may prescribe various topical or oral antibiotics. Acne, clogged pores, or other mild issues may be solved with proper grooming and treatment of the area with a topical ointment. Your veterinarian may also prescribe that your cat’s hair be trimmed or shaved during treatment if the condition is severe. 

For bacterial or fungal infections of the skin, your vet may prescribe special antibiotic baths. For fungal infections in particular, there are special solutions, or dips, that can be applied at the vet’s office and at home with special training. For many of these solutions, it will be important to let your cat thoroughly dry before they groom themselves which may necessitate the use of a cone or other movement limiting apparatus. Oral antibiotics may also be given as part of a series of treatments for severe conditions.

Treatment of Allergic Reaction

The immediate treatment for vesiculopustular dermatoses in cats caused by an allergic reaction is stopping the previous course of medication. Depending on your cat’s condition and overall health, your veterinarian may also attempt to manage the reaction with antihistamines or other drugs that reduce or eliminate the effects of the immune system’s overreaction. 

Treatment of Other Conditions that cause Vesiculopustular Dermatoses

Additional courses of treatment will be prescribed if the underlying condition is due to another disease, such as lupus, cancer or an autoimmune condition. Treatment for each of these serious conditions must be tailored to your cat’s specific medical needs. It will be important to discuss in detail and thoroughly follow instructions on prescribed regimens.

For many causes of vesiculopustular dermatoses in cats, the outcome and prognosis is good. Topical and oral solutions cure most minor conditions and altering medication can eliminate allergic sources. After the swelling and blister begins to subside, you may notice hair loss at the site of the vesiculopustular dermatoses. This should improve as time passes. For major underlying disease, prognosis will vary, but is typically good with careful adherence to all prescribed courses of medication.