Intralymphatic Immunotherapy Improves Symptoms but Not Quality of Life in Allergic Rhinitis

Intralymphatic immunotherapy (ILIT) reduced combined symptom and medication scores compared with placebo in patients with allergic rhinitis but did not significantly improve quality of life, according to a systematic review and meta-analysis of randomized controlled trials (RCTs) published in the American Journal of Otolaryngology.

The investigators noted that subcutaneous immunotherapy (SCIT), which they described as the gold standard for allergic rhinitis, is limited by long treatment duration and poor adherence, and that ILIT has emerged as a time-efficient alternative. Most included trials used a short ILIT course of 3 injections, with a few adding a booster dose.

The analysis included 16 RCTs with 606 patients; 13 compared ILIT with placebo and 3 compared ILIT with SCIT. Among 7 trials reporting the primary outcome, the Combined Symptom and Medication Score, ILIT was associated with a significant reduction vs placebo (standardized mean difference, −0.51; 95% CI, −0.82 to −0.20), corresponding to a mean reduction of 1.32 points. Four trials assessing the Rhinoconjunctivitis Quality of Life Questionnaire showed no significant difference between ILIT and placebo.

In head-to-head comparisons, the investigators reported that ILIT and SCIT had similar short-term effects, but that SCIT appeared more durable at longer follow-up. Local swelling was more than 4 times as common with ILIT as with placebo, whereas urticarial reactions, abdominal symptoms, fatigue, headache, and eye or nasal symptoms did not differ significantly. Total adverse events were 58% lower, in relative terms, with ILIT than with SCIT, although that comparison was based on only 3 trials.

The authors noted that certainty is limited by the small number of head-to-head trials; heterogeneity in allergens, dosing schedules, follow-up timing, and booster use; high risk of bias in some trials; and inconsistent adverse-event reporting. An assessment of publication bias for the primary outcome also found major asymmetry among studies. The authors called for further head-to-head trials to define the long-term role of ILIT.

Source: Almezher MU, Alharbi F, Alshngeetee A, et al. Intralymphatic immunotherapy (ILIT) versus standard care or placebo in allergic rhinitis: a systematic review and meta-analysis of randomized controlled trials. Am J Otolaryngol. Published online October 19, 2026. doi:10.1016/j.amjoto.2026.104969