TDK conference 2020

Equine atopy is a rare, chronic disease that requires lifelong therapy. Understanding its pathomechanism and finding safe and effective treatments have gained interest in veterinary dermatology. Nowadays intradermal tests, that have been the gold standard for identifying allergens are being replaced by serum allergy test and the role and interpretation of these serological methods need to be re-evaluated. Due to the complex therapeutic approach, allergen-specific immunotherapy based on serum allergy testing is a possible choice, that has been known to reach 60-80% success rates in equine patients. Considering long term safety, cost-efficiency and its doping-free status, allergen-specific immunotherapy should be preferred over antihistamines and glucocorticoids.

In our retrospective study we collected and evaluated data about the use of serum allergy tests and allergen-specific immunotherapy in Hungary from 2005 to present, where we used the serum allergy test cases of two Hungarian laboratories. 144 samples were submitted from 35 veterinarians. Four out of 13 contacted veterinarians participated and 18 online questionnaire were filled out by them. A total of 6 horses could have been defined as atopic based on standard inclusion criteria. In cases, where a definitive diagnosis could have been established retrospectively, allergen-specific immunotherapy appeared effective (success rate 4/4, 100%).

We did not reveal a definite allergen-specific pattern on the horses with atopy versus other cases evaluated by serology. These findings suggest that serum allergy testing is useful in atopic patients for identifying the causative allergens as well as assembling them for immunotherapy. Although further studies are warranted, these results indicate that allergen-specific immunotherapy based on serum allergy testing could be a first choice instead of a last resort in these cases.