What is Atopy:
Atopy is an inflammatory skin condition where animals will react to things in the environment (e.g. pollens, moulds, spores, grasses) which typically would cause no skin irritation. The agent causing the reaction is referred to as an allergen. Often animals with atopy will be allergic to more than one thing. Dogs are more prone to this condition than cats but it can be seen in both species.
These allergens gain entry to the skin via a defective skin barrier. The allergens are presented to the immune system which leads to an inflammatory response at the skin causing this itching and scratching.
There is a big genetic component to this disease and some breeds are more at risk of developing atopy. These breeds include: Staffordshire bull terriers, German Shepherds, Dalmation, Golden Retriever, West Highland Terrier, Beagles, Shar pei, Labrador, Lhaso Apso, Cairn Terrier, Shih Tzu, Boxer and Pug.
Features of Atopy:
• Chronic itching – this may start with no lesions and can have variation in intensity over time. Often worse in warmer times of year in QLD.
• Young age of onset – itching in response to environmental triggers tends to develop earlier in life (less than 4 years in most cases)
• For dogs: area involved – common areas of manifestation are feet, armpits, under abdomen, face (eyes and mouth), around anus – typically the lower back and ear margins are not involved. Cats don’t have as characteristic patterns as dogs.
• Chronic ear problem – some dogs will present with only this feature.
• Responds well to steroids – often with environmental allergies dogs and cats will respond rapidly to steroids. Food allergies can have a bit more variable response.
• Chronic yeast infections – these organisms live on normal skin surfaces, however when the skin barrier is damaged or broken it allows them to proliferate. This results in smelly, thickened skin.
• Secondary infections – due to chronic itching and damage to the animals skin barrier they will also often develop secondary bacterial infections which can appear as small pimples or pustules on the skin surface.
• Cats – constant overgrooming
The biggest feature you will often notice at home is itching. Itching can be seen as biting, rubbing, gnawing, licking and chewing behaviour from your pet. This behaviour causes damage to the skin resulting in signs of hair loss, red skin, erosions, scaling, thickened skin, change in pigment and more.
How it is Diagnosed:
It can be difficult to diagnose atopy. Often this diagnosis is made based on clinical signs (e.g. young onset, breed predisposition, response to steroids) and exclusion of other causes, e.g. food allergy, insect allergy, mites, contact dermatitis, infections, autoimmune disorders.
Intradermal allergy testing can also be performed to discover which allergens your pet is reacting to. This then helps with certain treatment methods.
How is it Treated:
Atopy is a multifactorial condition meaning it involves your pet being allergic to thing/s in the environment, a defective skin barrier and often secondary bacterial/yeast infections. All three aspects must be considered to create an effective treatment plan.
1. Immunotherapy – once intradermal skin testing has been performed a specific allergy vaccine can be made and given to your pet. This helps to desensitize them to the allergens which are making them itch. They will be given a course of vaccinations which help to either resolve or completely control their clinical signs/itching.
2. Medication – an anti-inflammatory medication can also be used to help suppress the clinical signs. There are pros and cons to these types of medications being used, especially long-term, and it will be discussed with you by a veterinarian if this is the best treatment option for you pet.
3. Infection control – treating any secondary infections is a very important part of treating atopy. Topical treatment, shampoos/rinses or oral medications will be used depending on your pets’ case and needs. Often cytology is used to determine numbers and types of infections present.
4. Skin barrier function – often with atopy the animal will have some type of abnormality in their skin barrier making them more susceptible to penetration of allergens and secondary infections. Whilst it can not be completely restored, the skin barrier can be improved with things like prescription skin diets and oral supplements, e.g. fish oil/omega 3+6. More gentle and nourishing shampoos/conditioners such as oatmeal based ones can also help improve the skin hydration and relieve some of the itchiness.