What is it?
In the last 10 years, many advances have been made in veterinary medicine, especially in the areas of dermatology and immunology. Dermatology is the study of diseases that affect the skin and haircoat. Immunology is the study of the immune system which protects animals from bacterial and viral infections. AISD results from a disorder of the immune system and the skin. We currently diagnose severe distinct syndromes such as pemphigus, pemphigoid, systemic and discoid lupus erythematosus.
In AISD, the animal’s body recognizes its own skin as foreign. As a result of this abnormal immune response, the skin is damaged. In a sense, the animal is trying to reject its skin, just as it would try to reject a viral or bacterial infection.
Why does the animal’s immune system recognize its own body as foreign? So far, we cannot answer that question. Various explanations have been proposed which include genetic, environmental, drug and viral factors. In dogs, there is some evidence for a genetic component, as AISD is seen more commonly in certain breeds (Akitas, Collies, Shelties, Chows, Dobermans).
Signs
Most cases of AISD occur in mature animals. The skin lesions first appear as small red spots that rapidly form a blister, then a pustule or pimple, and finally a crust. In most cases, the major lesions noted by the owner are red spots, ulcers and thick crusts (scabs) that form over the spots. The crusts usually start on the nose, around the eyes and on the ear flaps. Lesions may also involve the footpads, mouth, anus and genitals. Itchiness is variable, as some pets are not bothered at all while others are constantly rubbing and scratching. Other signs commonly noted are depression, lethargy, anorexia, lameness, enlarged lymph nodes and fever.
Diagnosis
The definitive diagnosis of AISD should always be made prior to treatment as numerous other diseases can look like AISD. Also, the treatment for these diseases can seriously harm your pet and exacerbate other skin diseases. Therefore, a definitive diagnosis should be made so that the correct and appropriate treatment(s) can be started.
Several tests are necessary to diagnose AISD. Blood tests along with cultures and skin biopsies are needed to diagnose if and which AISD is present. Sometimes, due to the waxing and waning nature of the AISD, the initial biopsy results are negative making it necessary to perform more biopsies at a later time.
Treatment
Once the diagnosis has been made, several treatments are available. Treatment involves using different medications that suppress the abnormal immune response and, therefore, are called immunosuppressive drugs. Each drug available has its advantages and disadvantages. They are all very potent agents and can cause serious side effects with chronic use. A baseline blood panel will be done initially and periodically during treatment to monitor for adverse drug effects.
Prognosis
In most cases, pets with AISD can be controlled so that their skin is normal with only rare flare-ups. However, they have to stay on some treatment for life. In addition, there are some cases that cannot be controlled with the treatments currently available. At the present time there is no test to determine which dogs will respond to treatment and which ones will not. It may be necessary to try several different drugs or combinations of drugs before you will know whether or not your pet’s disease can be controlled.
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