Allergen Immunotherapy Promising for Atopic Dermatitis

Adjunctive allergen immunotherapy (AIT) may improve disease severity and quality of life in patients with atopic dermatitis (AD), according to study findings published in the Journal of Allergy and Clinical Immunology.

Investigators conducted a systematic review and meta-analysis regarding the effectiveness and safety of AIT—subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT)—compared with no AIT (placebo or standard care) for patients with AD, as part of the American Academy of Allergy, Asthma & Immunology (AAAAI)/American College of Allergy, Asthma and Immunology (ACAAI) Joint Task Force on Practice Parameters (JTFPP) 2022 AD guideline update.

The researchers performed a literature search for relevant published or unpublished randomized controlled trials (RCTs) through December 12, 2021. Outcomes included clinician-reported severity (the clinician-adjudicated domains of SCORing AD [SCORAD] or eczema area and severity index were prioritized vs investigator global assessment), patient-reported severity (patient-oriented eczema measure), itch, sleep, eczema-related quality of life (Dermatology Life Quality Index [DLQI], and adverse events.

The reviewers independently rated the risk for bias per outcome for each study, which was conducted according to Cochrane and Grades of Recommendation Assessment, Development and Evaluation (GRADE) guidance.

A total of 23 RCTs with 1957 patients were included in the analysis. The trials, which were conducted in 13 countries in 4 continents, added either AIT or placebo to standard care with topical treatments (midpotency topical steroids or topical calcineurin inhibitors).

Among the included studies, 22 RCTs (n=1801) compared AIT vs no AIT and involved a combination of clinician-reported AD severity and patient-reported itch and sleep disturbance. AIT likely improved the probability to lower baseline AD severity by 50% or greater vs no AIT (40% vs 26%, relative risk [RR] 1.53 [95% CI, 1.31-1.78], moderate certainty), with comparable estimates of effect for SCIT and SLIT (P_interaction =.63).

In addition, 8 RCTs (n=629) addressed the effects of AIT compared with no AIT on health-related quality of life (per DLQI and a minimally important difference [MID] of 4). AIT “probably improved” DLQI by 4 or more points vs no AIT (56% vs 39%, RR 1.44 [95% CI, 1.03-2.01], moderate certainty).

AIT’s impact vs no AIT for pruritus was evaluated in 3 RCTs (n=113). AIT may decrease itch by 50% from baseline compared with no AIT, although the evidence is uncertain (25% vs 19%, RR 1.29 [95% CI, 0.84-1.98], low certainty). Also, 4 RCTs (n=165) assessed flares leading to systemic corticosteroid use. AIT’s effect, compared with no AIT, was very uncertain (20% vs 22%, RR 0.94 [95% CI, 0.30-2.94], very low certainty).

A total of 12 RCTs (n=1041) in AD and 87 RCTs in rhinitis and asthma evaluated adverse events from AIT and were mainly characterized as local reactions. AIT was associated with an increase in local adverse events vs placebo (RR 1.65 [95% CI, 1.48-1.64], high certainty), with similar relative effects observed for SCIT and SLIT P_interaction =.42) and different absolute effects (SCIT: 66% vs 41%; SLIT: 13% vs 8%).

Among several study limitations, not all populations had the same baseline severity of AD, conference abstracts were included, and the data were sparse for itch, sleep, and flares. In addition, data for direct AD evidence addressing adverse events was sparse.

“This systematic review and meta-analysis provides moderate-certainty evidence that adjunctive allergen immunotherapy results in important improvements in AD severity and quality of life,” stated the researchers. “This supports a multidisciplinary and shared decision making approach to optimal AD care.”

Disclosure: Several of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.