A lot of things can make a dog itchy: fleas, mites, skin infections, and food allergies, to name a few.
One of my favorite things about working in veterinary dermatology is being able to help animals that have been suffering from intense itchy skin for a very long time and working hand in hand with the owners to develop the best long-term plan for the animal and owner.
After veterinarians rule out all other causes of itching in your dog, then they can make a diagnosis of atopic dermatitis.
What Is Atopic Dermatitis?
Atopic dermatitis is a skin condition that affects between 10 percent and 20 percent of dogs and cats. It is a long-term condition that is associated with allergies. Many of the allergens that cause atopic dermatitis are normally harmless components in the environment, such as grass, mold, or dust.
“The most common clinical sign we see associated with atopic dermatitis is itching, followed by recurrent infections of the skin. The itching is often tied to a particular season at first, but with time, it usually ends up occurring year round,” confirms Dr. Dariy.
Before making a diagnosis of atopic dermatitis, veterinarians will conduct a variety of diagnostic tests to rule out other diseases. They may recommend a food trial, where the animal is put on a hypoallergenic diet and potential allergens are gradually introduced in a very controlled way, to rule out food allergies.
“In our animal patients, the most common allergens seen are house dust mites, storage mites, house dust, grasses, trees, weeds, cat skin, corn pollen, fungus, insects, and even wool, and tobacco,” notes Dr. Dariy.
What Causes Atopic Dermatitis?
Atopic dermatitis is caused by an overactive immune system response to an allergen, but the underlying cause of allergies is a subject of debate.
“One theory about why the immune system becomes more responsive, called the barrier dysfunction theory, proposes that the skin normally functions like a brick wall to keep everything out that it should. With atopic dermatitis, there is a breakdown in this normal barrier, allowing things in the environment to penetrate deeper into the skin and cause an increased inflammatory response,” explains Dr. Dariy.
Other factors that play a role include the environment the animal was raised in and the breed of the animal. Some susceptible breeds include Chinese Shar-Pei, wirehaired fox terrier, golden retriever, Dalmatian, boxer, Boston terrier, Labrador retriever, Lhasa Apso, Scottish terrier, Shih Tzu, and West Highland white terrier.
How Is Atopic Dermatitis Treated?
There are many routes of treatment for atopic dermatitis. Our recommendations vary depending on the severity of the case along with the health history of the patient. Most treatments are not specific to the allergens the patient is allergic to. The treatment is designed to decrease the inflammation that occurs in the skin.
Another option for treatment is allergen immunotherapy, which is the same process as used in human allergy shots. Before this can begin, allergen testing must be completed to see what the animal is allergic to. A blood test can be used for this.
Allergen immunotherapy is the most natural type of treatment available since we are injecting small doses of only what they are allergic to. In the long term, there are usually fewer side effects with allergen immunotherapy than there are with other treatments.
Once the allergens are identified, the allergy shots can be administered at home after the owner is shown how to give the injections.
Response time after treatment is highly variable depending on the treatment method. Some may respond to allergen immunotherapy within one month, while other patients may take up to a full year to respond. Allergen immunotherapy takes longer since it is working with the body’s natural immune system to change the inflammatory response that occurs.
Even with treatment there can be complications associated with this disease and medication side effects. The most common of these complications is recurrent bacterial or yeast skin infections.
Can We Cure Atopic Dermatitis?
Everyone must realize that animals that have atopic dermatitis are bound to get secondary problems, ranging from simple secondary infections to more serious issues such as immune-mediated disease or tumors caused by continued inflammation.
Allergies can be frustrating to treat because it is a battle against the immune system. Animals with allergies may always show some signs, even with treatment.
“The most important fact is that we will most likely never ‘cure’ allergies with any of our treatments, but we will manage them for the rest of the animal’s life. Our ultimate goal is to significantly decrease their itchiness and frequency of secondary infections,” explains Dr. Dariy.