more than skin deep: pemphigus foliaceus
Pemphigus foliaceus is a common skin disease in cats and dogs. It is autoimmune in nature, meaning that the body’s own immune system mounts an inappropriate attack against normal layers of the skin. While there are several different types of pemphigus diseases, pemphigus foliaceus (PF) is considered a superficial pemphigus, unlike other pemphigus conditions that affect deeper skin tissues.
Pemphigus foliaceus is the most common immune mediated skin disease in cats and dogs, and is characterized by skin crusts and ulcers around the eyes, ears, footpads, groin, and muzzle. Additionally, cats can have lesions around their toenails. In some cases, PF can be generalized about the entire body.
While PF is considered a superficial skin disease, the lesions it causes should not be taken lightly. Crusts and ulcers can be quite profound and painful, and the lesions are always at risk of becoming infected. Pets with uncontrolled PF deal with uncomfortable sores that may interfere with their quality of life.
While we do know that PF is immune mediated, we do not usually know the direct cause. There are some potential triggers for PF, however, including UV light exposure and some drug therapies. There do not seem to be breed dispositions in the cat, but Akitas and Chow Chows are the dog breeds that are more prone to developing PF.
While your veterinarian may have a hunch that pemphigus foliaceus is to blame for your pet’s skin lesions, the preferred way to achieve a definitive diagnosis is via skin biopsy of the lesions. Some types of pemphigus can be difficult to differentiate just by looking at the lesions, so a definitive diagnosis from a skin biopsy is important.
Treatment of PF centers on suppressing the immune system of the affected pet. We generally try to do this using steroids, but occasionally, other kinds of immunosuppressants are needed. In addition, oral and/or topical antibiotics will be needed to treat underlying infection that is present in many cases of PF.
Steroids, such as prednisone, can cause short and long term side effects. Increased water intake and increased urination (polydipsia/polyuria), and increased appetite can be frustrating side effects for owners to deal with, and long term use of steroids is associated with the development of diabetes, obesity, and Cushing’s syndrome.
Though there is the potential of side effects from the treatment of PF, it is important to remember that between forty and eighty percent of cases can be well controlled, and some patients will be able to discontinue medication once the clinical signs have abated. Owners of pets with PF will need to have an abundance of patience with the treatment, as often it can take months to achieve resolution.
All of that being said, the expense and side effects of the medications required to treat PF can be a major stress to owners who do not have pet insurance. Additionally, pets may not achieve a quality of life that is acceptable to owners. For these reasons, a diagnosis of PF may eventually lead to euthanasia for many pets, depending on the severity of the condition and the response to treatment.
If your pet is diagnosed with pemphigus foliaceus, do not despair! Just keep in mind that the treatment may be prolonged, and do your best to follow your veterinarian’s recommendations. A referral to a doctor who specializes in dermatology may be helpful, so if there is a board certified veterinary dermatologist in your area, ask your veterinarian to refer you if you are having trouble achieving resolution of the condition.