Paul B. Bloom, DVM, DACVD, DABVP (Canine and Feline Specialty)
Allergy, Skin and Ear Clinic for Pets, Livonia, MI; Department of Dermatology, Michigan State University, East Lansing, MI, USA
Assuming the diagnosis of atopic dermatitis (AD) has been established (that is another whole lecture) the treatment of the pruritic dog has changed. While in the past we focused only (or mostly) on the hypersensitivity component, we now realize we must address the cutaneous barrier dysfunction that is present.
Treating a dog with AD is like eating at a buffet. You can eat whatever you want but not everything that is offered. If you don't like broccoli, then don't eat it - but if you are hungry after your meal - then you will have to eat the broccoli. This concept is also applies to treating AD - you can/do have whatever you want but not everything. By explaining this to the owner, they feel involved in the treatment plan for their dog. Let's choose the most user friendly, safest approach and if this fails, then they have to choose another option.
Treatment options for dogs with atopic dermatitis include - (please note that these therapies are used as a preventative so they should be instituted before clinical signs recur):
1. Good skin care
a. Restore barrier function.
b. Wiping the dog off after coming in from outdoors
c. Clipping the hair coat to a short length (10 or 15 blade), which helps to decrease exposure to and contact with environmental triggers (allergic and irritant).
d. Clothing all the time and boots outdoors.
e. Bathing with a hypoallergenic veterinary shampoo that contains moisturizers or barrier repair ingredients (e.g., a shampoo that contain phytosphingosine) weekly or more.
f. Follow the bath with a humectant or a product that contains barrier repair ingredients (triple lipids, phytosphingosine, topical omega fatty acids).
i. In humans - best applied within 2 minutes after finishing the bath for maximum effect.
g. Topical moisturizers unrelated to bathing.
i. Allerderm spot on® - Virbac, Dermoscent Essential 6 Spot-On Skin Care®- Aventix or Douxo Seborrhea Spot-on® Sogeval are examples
a) Fatty acid supplementation - try an omega 3 product (dosed at 18 mg/kg of EPA daily) for 3 months, and if it is ineffective, then try a product with a combination of an omega 3 and 6 (double bottle dose or Hills J/D diet).
h. Bathing is helpful to decrease antigen load and bacterial colonization.
2. Identify and prevent/manage the triggers (ectoparasites, food, infection (bacterial/Malassezia).
a. If the dog has environmental triggered AD, specific immunotherapy is appropriate if the symptoms are present for more than 2 or 3 months/year and is severe enough to need corticosteroids or cyclosporine for symptomatic control.
b. If the dog has a food trigger - avoid those foods.
c. Good flea control especially if the dog has flea bite hypersensitivity.
3. During acute flares - treating infection and inflammation is necessary. Therapy would include antibiotics, antifungals and glucocorticoids along with the above recommendations.
4. Treatment options for symptomatic relief of dogs with AD without secondary infection are
a. Glucocorticoids.
b. Modified cyclosporine.
c. Antihistamines/tricyclic antidepressants - there are a variety of antihistamines available that may help mildly pruritic dogs.
Summary from the ACVD Task Force on AD
Treatment of Acute Flares of Canine Atopic Dermatitis
1. Identification and avoidance of flare factors:
a. Identification and elimination, whenever possible, of allergenic flare factors (fleas, food and environmental allergens).
b. Evaluation of use of antimicrobial therapy if clinical signs of infection or colonization with bacteria or yeast are present on the skin or in the ears.
2. Improvement in skin and coat hygiene and care:
a. Bathing with a nonirritating shampoo.
3. Reduction of pruritus and skin lesions with pharmacological agents:
a. Treatment with topical glucocorticoids, especially for localized lesions, as needed to control signs.
b. Treatment with oral glucocorticoids, especially for widespread or severe lesions, as needed to control signs.
Treatment of Chronic Canine Atopic Dermatitis
1. Identification and avoidance of flare factors:
a. Dietary restriction-provocation trials in dogs with nonseasonal signs.
b. Implementation of an effective flea control regimen in areas where fleas are present.
c. Performance of allergen-specific intradermal and/or IgE serological tests to identify possible environmental allergen flare factors.
d. Possible implementation of house dust mite control measures, if relevant and feasible.
e. Evaluation of use of antimicrobial therapy if signs of infection or colonization with bacteria or yeast are present on the skin or in the ears.
2. Improvement in skin and coat hygiene and care:
a. Bathing with a nonirritating shampoo or an antiseborrheic/antimicrobial shampoo, depending on the skin lesions seen.
b. Dietary supplementation with essential fatty acids.
3. Reduction of pruritus and skin lesions with pharmacological agents:
a. Treatment with topical glucocorticoids or tacrolimus, especially for localized lesions, as needed to control signs.
b. Treatment with oral glucocorticoids, cyclosporine or subcutaneous interferon, especially for widespread or severe lesions, as needed to control signs. These agents would not normally be combined together.
c. Use of steroid-sparing agents, such as essential fatty acids, Chinese herbs and antihistamines, if glucocorticoids are being used as a long term treatment option.
4. Implementation of strategies to prevent recurrence of signs:
a. Avoidance of known flare factors, as identified above.
b. Consideration of preventive pharmacotherapy, if feasible and relevant.
c. Implementation of allergen-specific immunotherapy, if feasible. This can be used alongside all the above treatment options in an attempt to provide long term amelioration of the aberrant immune response.
References
References are available upon request.