Long-term effects of intralymphatic immunotherapy (ILIT) on canine atopic dermatitis

Subcutaneous allergen immunotherapy (SCIT) is an established and efficacious therapy for canine atopic dermatitis (AD). In humans, intralymphatic immunotherapy (ILIT) was reported to be associated with fewer and less severe adverse effects than subcutaneous allergen immunotherapy and to be efficacious for several years after three intralymphatic injections.

To evaluate safety and effects of ILIT in a case series of dogs with (AD).

Fifty one privately owned dogs with AD.

Dogs received injections of 0.2 mL alum-precipitated allergen extract into the popliteal lymph nodes at monthly intervals for 3-5 months. Lesion scores, pruritus and medication scores were determined before and at three and 12 months after beginning immunotherapy, and compared in a per protocol analysis (PP) and an intention-to-treat analysis (ITT).

Twenty two dogs completed the study and 29 dogs did not fulfil study completion criteria due to lack of a final study visit (21 of 29) or due to insufficient improvement (14 of 29). All scores improved during the study with both analyses. For pruritus and Quality of Life scores this improvement was significant with both analyses; for Canine Atopic Dermatitis Extent and Severity Index (CADESI)-03 values and medication scores only with PP. The only rare adverse effects observed included mild swelling of the lymph node post-injection and increased pruritus.

ILIT is safe and feasible, and provides long-lasting relief in some atopic dogs with a limited number of injections.