Front Range Animal Hospital
418 Third Street, P.O. Box 326
Monument, CO 80132-0326
(719) 481-3455

Allergic Dermatitis

Allergic dermatitis is inflammation of the skin due to exposure to an allergen (a substance that an animal is allergic to). By far the most common cause of allergic dermatitis is Colorado pets is atopy­an allergic response to allergens in the environment that are inhaled or absorbed through the skin. Common substances include grass, weed,and tree pollens, house dust, feathers, wool and cigarette smoke. Occassionally the alllergic dermatitis is due to a food allergy and some pets have both problems.

The primary symptom of allergic dermatitis is itching. Pets will lick, chew, or scratch their itchy skin resulting in hair loss, skin redness, and sometimes open sores. Common areas to be affected are the muzzle, eyes, ears, feet, armpits, abdomen, and legs. Allergic rhinitis (sneezing, runny nose), while common in people, is rare in pets. Allergic dermatitis is usually seasonal but may become a yearround problem over time. The tendancy to develop allergies is suspected to be hereditary.

The first step in dealing with allergic dermatitis is to rule out other causes of itchy skin. A veterinary exam is made to evaluate the skin for infection and flea infestation. Skin scrapings might be made to rule out skin parasites and fecal examination may be done to check for intestinal parasites. If the diagnosis is still in doubt, blood or skin testing for allergies can be done. Sometimes a trail of 3-6 weeks on a hypoallergenic diet must be done to test for underlying food allergies.

The most common and effective medication for allergic dermatits is corticosteroids such as prednisolone. Initially the prednisolone is given daily (orally) until the itching is controlled (usually 5-7 days) then the medication is tapered to the lowest dose possible that can be given every other day. Longterm dosing of prednisolone daily should never be done without the doctorıs orders­it is better to go with a slightly higher alternate day dosage than daily dosage of a lower amount. Side effects are occassionally seen with prednisolone and include increased thirst and urinations and increased appetite. These side effects are most noticeable on the higher doses. Occasionally long-acting steroid injections can be used instead of the pills. This is especially useful in cats which are more resistant to the side effects of the corticosteroids.

Other medications can be tried for pets whose allergies are not controlled with corticosteroids or if the medication side effects are too annoying. These include antihistamines and essential fatty acids. Typically these medications do not work as well as corticosteroids but are helpful in some pets. Also a hypoallergenic diet may be tried to decide if food allergies are causing the dermatitis. Often food allergies cannot be controlled with corticosteroids and are usually yearround (nonseasonal) from the beginning. Allergy testing and allergy ³shots² (desensitization) is another option for the patient that is difficult to control.

Weekly baths should be considered in dogs with extensive body involvement. Using a mild hypoallergenic shampoo with moisturizers, such as HyLyt efa, can remove the offending allergens from the skin. If excessively dry skin is involved, as Alpha-Keri moisturizing rinse after bathing can be used, as dry skin will aggravate the itching of allergies. Shampoos containing oatmeal (such as Aveeno) or cortisone can also be tried as a further help with the itching.

Allergic dermatitis can be a frustrating problem for the pet and itıs owner as it is a lifelong condition that cannot be cured, but with patience and effort, the right therapy for each pet can be determined to keep the problem under control.