Environmental Allergy – Atopic Dermatitis
By Amber Chavez
Allergy season is now in full force with the onset of spring. Many of us are experiencing, a stuffy nose, dry eyes and sinus headaches. Our pets too can experience allergies from environmental triggers, which are known as antigens. However, most veterinary skin disorders are unique. Environmental allergies can manifest in dogs via itchy skin, red itchy ears with a foul smell, head shaking, hair loss and dandruff. You may notice your dog licking, scratching, biting, chewing or rubbing in an effort to sooth the itchy feeling. Not only can we see red itchy ears, but often we will see chronic otitis also known as chronic ear infections. According to an article in the Journal of Veterinary Dermatology, “In 43% of allergic dogs with chronic otitis (ear infections), the signs of otitis were noticed by the owners before the other signs of allerg[ies]” (Favrot). Pets that are licking and scratching can actually make things worse. Bacteria and yeast are part of the normal flora that keeps your pet’s skin healthy. With the onset of allergies, the protective barrier function of the skin can be weakened. With the skin in a weakened state, the normally non-harmful bacteria and yeast of the skin have the opportunity to proliferate into large numbers. The growing numbers of these bacteria and yeast lead to further itchiness and inflammation of the skin. Thus, chronic yeast and or bacterial infections of the skin can be great indicators of a pet with allergies.
Environmental allergies have a strong connection to the changing of seasons. Most pets with allergies will be significantly more pruritic (itchy) in the spring and summer, when plants and grasses are in bloom. In the winter and late fall, symptoms can often decrease in severity. However, more factors can affect the severity of allergies other than the season. Allergies can worsen or even appear as an animal ages or is placed in a new environment, such as moving from California to Mississippi. However, your veterinary dermatologist has many options to assist in pin pointing some of the issues your particular pet faces.
Intradermal skin testing is the gold standard for diagnosing the areas of the environment that may be causing your pet discomfort. According to an article in the Journal of Rhinology and Allergy, “It generally is noted that the advantage of skin testing is that it uses testing to an end organ, is less expensive, is more sensitive, and provides immediate results” (American). This is an important step in the process of relief because treating the secondary bacterial and yeast infection will be a continual cycle unless the underlying problem can be identified. In recent years, a blood test for environmental allergen identification has become available. However, the skin test has proven to be more reliable due to inconsistency among labs across the country. It is important to work with your veterinary dermatologist to have testing performed and treatment to manage the allergies, for the benefit of you and your pet.
It is very important to realize that much like human allergies, allergies in our pets can never be cured, but we can identify and manage them. Your veterinary dermatologist has many options available for treatment. Apoquel, an immunomodulatory drug is a great medication for dogs that has been life changing in the relief it offers to many. Steroids are another option your veterinary dermatologist might use. Your veterinary dermatologist would be able to discuss all available medications for your pet. Lifestyle changes such as providing supplements (ie fish oil) and frequent medicated baths can also offer relief. As one could imagine, treatment can be tailored and thus more successful once the offending allergens are known. The intradermal skin testing provides a method of treatment very specific to the allergens causing problem in your pet. Once your veterinary dermatologist knows what is causing your pet such discomfort, they can begin a treatment of desensitization via injections. Exposing an animal to a small but frequent amount of the antigen causing the problem, can calm the immune system and thus give some relief.
In the sensitization phase, the skin that acts as a barrier, is compromised and the allergens cross the skin where they are processed by Antigen presenting cell (“The Itch Cycle.”). “The diagnosis of this condition is difficult because none of the typical signs are pathognomonic”(Favrot). This means the signs are not specific to one disease. However, manifestation of allergies can often be seen at the feet, ears and abdomen.
It is important to schedule a consult with your veterinarian when you notice excessive itching or licking in your pet. The options available for management of environmental allergies are abundant and improving all the time. Environmental allergies remain a very frustrating problem that has no cure. However, understanding the condition and the available options can offer much relief to you and your pet. Once you begin seeing a dermatologist, the relationship and knowledge you gain can go a long way in improving the quality of life of your pet.
American Journal of Rhinology & Allergy, Volume 29, Number 5, September/October 2015, pp. 362-364(3)
"Allergic Diseases." Mayo Clinic. N.p., n.d. Web. 16 May 2016.
Favrot, Claude, Jean Steffan, Wolfgang Seewald, and Federicca Picco. "A Prospective Study on the Clinical Features of Chronic Canine Atopic Dermatitis and Its Diagnosis." Veterinary Dermatology 21.1 (2010): 23-31. Web.
"The Itch Cycle." The Itch Cycle. Zoetisus, n.d. Web. 11 May 2016.