Wednesday, October 22, 2014

Atopic Dermatitis Part 1

Allergies can be one of the most frustrating conditions pet owners face. Many times there are no cures, just management. While we can control the food and flea exposures it is extremely difficult to control environmental allergies. Atopic Dermatitis (or atopy) is allergies to environmental agents. When we talk about the environmental allergens these can range from pollens, to dust mites, to animal dander (yes, dogs can be allergic to cats too!), and mold. It is nearly impossible to avoid contact with these, however when we know what the specific allergy is we can try to minimize contact.
Photo Source
Typically atopy will begin with younger dogs, but again can be seen across all age groups.  Symptoms include intense itching, reddening of the skin, increased pigment (or coloring) of the skin, and hair loss. The areas most commonly affected are feet, face and under portion of the body. The skin may also become very thickened in these places as well. Depending on the allergen the symptoms may occur seasonally. Dust mites and other pet dander however may be present year round.
Picture Source
A diagnosis cannot be made on symptoms alone. Many other conditions need to be ruled out first. Typically a full work up will be needed. This could include skin scraping to rule out mites, cytology to assess for bacterial or yeast infections as well as blood work to ensure there are no other underlying causes. It is definitely possible to have more than one condition going on at the same time. Without treating any underlying or secondary diseases it will be difficult to resolve the symptoms.
Photo Source
Allergy testing is the only way to determine what a pet is allergic to. There are two different methods of testing. One is very similar to people which is called intradermal skin testing. This is where small amounts of allergens are injected under the skin and then evaluated for response. If there is a large response the patient is considered allergic to that material. The downside of this procedure is that patients must be sedated and a large area must be shaved. The advantage is that this testing is usually very accurate. Another form of testing is a blood sample that can be submitted for analysis. This is becoming more accurate over time but still is not quite as accurate as skin testing. The advantage is that most general practices can perform this test and patients do not have to be sedated. The disadvantage is that many times this will not always indicate if the animal is actually allergic to the material or just showing a large amount of exposure.

**Next week we will pick up with what to do after allergy testing.**

No comments:

Post a Comment