Overview:

Pemphigus complex is a group of rare autoimmune skin diseases in cats. Autoimmune diseases are the result of an overactive immune response against the cat's own tissues resulting in the production of antibodies to epidermal adhesion molecules causing them to separate, leading to the formation of pustules. The name pemphigus is derived from the Greek word pemphix meaning bubble or blister.

There are three types of pemphigus that have been described in cats; pemphigus foliaceus (PF), pemphigus vulgaris (PV) & pemphigus erythematosus (PE). The type of disease depends on which layer of the skin is affected.

The most common is pemphigus foliaceus which affects the top layer of the skin.

Pemphigus erythematosus is the second most common form & is believed to be a milder form of pemphigus foliaceus in which the head & feet are affected.

Pemphigus vulgaris is very rare, producing deep ulcers rather than thick crusts. Lesions typically occur in the mouth & areas of trauma such as claw folds, armpits & groin. Secondary infections are common  and are often fatal.

Middle aged to older cats are most commonly affected by pemphigus complex.

Symptoms of pemphigus complex in cats:

The most common symptoms are pustules. The distribution of lesions in pemphigus foliaceus are fairly generalised whereas with pemphigus erythematosus they are limited to the head & feet & pemphigus vulgaris affects the mouth, claw folds, armpits & groin. [1]

Diagnosis of pemphigus complex in cats:

Your veterinarian will perform a physical examination of your cat & obtain a medical history from you. The diagnosis of pemphigus is based on skin biopsy findings.

Treatment of pemphigus complex in cats:

Treatment of pemphigus complex can be quite difficult. Immunosuppressive drugs such as oral prednisone are the first choice of treatment.

Topical steroids may be used in mild cases.

If remission is not achieved with the above medications, other therapies may be added such as chlorambucil. The dose will be gradually tapered back over time.

Antibiotics may be necessary to treat any secondary bacterial infections.

Side effects from the use of immunosuppressive drugs can be severe & close monitoring by your veterinarian is important.

References:

[1] Cat Health Encyclopedia - Edited by Lowell Ackerman.