By Matthew Kearns, DVM
My last article focused on the older treatments for atopic dermatitis with some of the treatments largely ineffective in more severe cases and, others, having too many adverse side effects. Very briefly, atopic dermatitis in pets is defined as, “a chronic, itchy, inflammatory skin condition that occurs in genetically predisposed animals,” or a rash associated with seasonal allergies. Here are some of the newer medications available for the treatment of atopic dermatitis.
Cyclosporine (Atopica®): cyclosporine is classified as an immunosuppressant but, overall, it is much safer than corticosteroids (cortisone derivatives) long term for the use of treating chronic atopic dermatitis. Cyclosporine prevents the activation of a certain type of white blood cell called T cells and the inhibition of certain chemicals called interleukins, as well as others. The main side effect is gastrointestinal (nausea, vomiting, diarrhea, flatulence). Cyclosporine has also been linked to increased risk of certain types of neoplasia (tumors, cancer) in certain breeds.
Oclacitinib (Apoquel®): oclancitinib is classified as a novel, selective immunosuppressant. Oclancitinib inhibits the enzyme janus kinase. Janus kinase acts as a signal for the immune system to attract cytokines, or mediators of inflammation. Specifically, oclancitinib inhibits a type of cytokine called interleukins. The interleukins inhibited are pro-inflammatory. There is a benefit to inflammation in immune responses to fight diseases however, the interleukins inhibited are responsible for itching and rashes associated with atopic dermatitis. At least 60% of dogs have responded with a substantial decrease in itching and rashes when oclancitinib is used long term.
Lokivetmab (Cytopoint®): lokivetmab is classified as an anti-canine IL31 monoclonal antibody, but technically lokivetmab is an allergy vaccine. “IL31” is short for interleukin-31. Interleukin-31 is a cytokine that specifically triggers pruritis, or itching in the brain. Injecting itchy dogs with lokivetmab, or antibodies against IL31 reduces itching in over 50% of dogs treated. Unfortunately, lokivetmab is not effective in preventing the rashes and skin infections. Therefore, secondary treatments (antibiotics, antifungals, medicated shampoos or sprays, etc) may be required to manage atopic dermatitis in some patients.
Allergy Specific Immunotherapy (ASIT): this refers to testing for what a patient is allergic to and attempting to desensitize them to those allergens. The testing can be either: serum (blood), or intradermal. Many veterinarians will be able to draw the blood needed to send out for testing. Intradermal testing is usually done under the guidance of a veterinary dermatologist. Testing should include both food and environmental allergens. This way we can avoid certain diets that would definitely cause a reaction, as well as desensitize the body to known environmental allergens with a customized injection or sublingual (under the tongue) drops. Both are quite effective.
I have found that some cases require short courses of some of the old school medications for “flare ups” at certain times of the year even if they are doing well on the new school treatments for most of the year. As always, check with your own veterinarian as to which treatment is best for your pet.
Dr. Kearns practices veterinary medicine from his Port Jefferson office and is pictured with his son Matthew and his dog Jasmine.