Atopic dermatitis

Atopic dermatitis, or atopy, is a common allergic skin condition in dogs. Typically, dogs are affected from about 1-3 years of age, but symptoms may appear at any stage of a dog’s life. The primary problem is a defective skin barrier which readily absorbs allergens from the environment. These allergens cause the dog’s immune system to overreact, similar to eczema in humans. In sensitised dogs, exposure to allergens (dust, pollens, etc.) via contact, ingestion or inhalation can trigger a skin reaction.

The skin becomes inflamed and irritated, usually causing an extreme itch. As the dog scratches or chews at the skin, bacterial and yeast infections may become established, and these secondary infections exacerbate the itch. The itch may be constant, seasonal or periodically flare up.

Atopy must be differentiated from other conditions causing itchy skin, such as fleas or flea allergy dermatitis. Your vet may recommend further testing or treatment trials to rule out these conditions.

Management

Unfortunately there is no cure for atopic dermatitis, it is a chronic condition requiring lifelong management and is often difficult and frustrating to treat. There are many approaches to management, outlined below, which are often combined to optimise the treatment outcome.

Apoquel

Apoquel is a new oral medication specifically designed to treat itching associated with allergic skin disease. It is a new class of medication without the major side effects of cotico-steroids. Apoquel works quickly to lessen a dog’s itch and the desire to scratch, and also decreases the associated redness and swelling of the skin.

The aim of Apoquel is to reduce a dog’s requirement for cortisone in the longer term. Twice daily medication is required for the first 2 weeks, then the dosage is tapered to once daily for maintenance therapy.

Cortisone

This is the most commonly prescribed medication for an itchy dog. It is a steroidal anti-inflammatory that reduces inflammation and itch, and comes in injectable, oral and topical forms. Although generally well tolerated by dogs, cortisone has the potential for serious side effects with chronic, long term use, and it is important to minimise the dose required to keep your pet comfortable. If your dog requires long term cortisone treatment, regular health checks and periodic blood tests are recommended to monitor for systemic side effects of the drug.

Topical cortisone (sprays and creams) have minimal systemic side effects and are very useful for discrete lesions in sparsely haired areas, but have limited effectiveness when the itch is generalised across the body.

Antihistamines

Antihistamines are a very safe option to help ease the itch, but unfortunately are effective in less than 30% of dogs. Can be useful in combination with other therapies.

Antibiotics

Antibiotics are frequently required to treat secondary skin infections, often in conjunction with cortisone treatment. Controlling the itch and bathing the skin with medicated products will help prevent secondary infections, but flare-ups are inevitable from time to time.

Immunotherapy (gold standard)

This involves referral to a specialist veterinary dermatologist, who will run tests to determine which specific allergens your dog reacts to, and develop a desensitisation vaccine unique to your pet. This option will require giving your pet regular injections over an extended period. It is expected that approximately 75% of atopic dogs will respond well to desensitisation, dramatically reducing the amount of medication required to control the itch.

Atopica

This is an immunosuppressive medication that suppresses the body’s allergy response. It is used for patients that require continuous high doses of cortisone to control the itch, or patients that suffer significant side effects of cortisone therapy. 

Diet

Prescription diets can be very successful in the management of atopic dermatitis. Some are hypoallergenic, and others include specific anti-oxidants and essential fatty acids for skin health. Alternatively, you could add fatty acid supplements (such as Megaderm), fish oil or flax seed oil to your dog’s regular diet.

Shampoos and conditioners/moisturisers

Generally speaking, due to your dog’s poor skin barrier and sensitive skin, you should try to restrict bathing to once a month. We recommend using an oatmeal-based shampoo and conditioner for sensitive skin, such as Aloveen. After bathing with the shampoo, briefly towel-dry your dog, then apply the leave-in conditioner to moisturise the skin – this is a very important aspect of maintaining a healthy skin barrier.

Sometimes your vet may recommend a medicated shampoo, particularly if the skin is very greasy or scaly, or there is secondary infection present. These are typically used once or twice weekly and may need to be left on the skin for 10 mins at a time.

Flea control

Maintaining regular, effective flea control is essential in the management of an atopic pet. Fleas will obviously exacerbate the itch and skin inflammation, and many atopic dogs also suffer from flea allergies. Our recommended product for flea control is Comfortis, a monthly chewable tablet that kills fleas instantly and keeps them off your pet for a full month. Supermarket products, especially flea rinses and collars, are inferior products and not appropriate for dogs with allergies.

If you have concerns about your dog's constant scratching and itching, please make an appointment to see a veterinarian.