Efficacy of House Dust Mite Sublingual Immunotherapy in Patients with Atopic Dermatitis: A Randomized, Double-Blind, Placebo-Controlled Trial

Abstract

Background: Sensitization to house dust mites (HDMs) is frequent in patients with atopic dermatitis.

Objective: To investigate the efficacy of sublingual immunotherapy (SLIT) with Dermatophagoides pteronyssinus extract in patients with atopic dermatitis sensitized to HDM.

Methods: In this randomized, double-blind, placebo-controlled trial, we enrolled 91 patients 3 years or older, with SCORing Atopic Dermatitis (SCORAD) score greater than or equal to 15 and positive skin test result and/or IgE to D pteronyssinus. Patients were stratified according to age (<12 and ≥12 years) to receive HDM SLIT or placebo for 18 months. Primary outcome was a greater than or equal to 15-point decrease in SCORAD score. Secondary outcomes were decreases in SCORAD and objective SCORAD, Eczema Area and Severity Index, visual analog scale for symptoms, and pruritus scale scores; Investigator's Global Assessment 0/1; and decrease greater than or equal to 4 points in Dermatology Life Quality Index. Background therapy was maintained.

Results: A total of 66 patients completed the study (35 HDM SLIT, 31 placebo). After 18 months, 74.2% and 58% of patients in the HDM SLIT group and the placebo group, respectively, showed greater than or equal to 15-point decrease in SCORAD score (relative risk, 1.28; 95% CI, 0.89-1.83). Significant SCORAD score decreases from baseline of 55.6% and 34.5% in HDM SLIT and placebo groups (mean difference, 20.4; 95% CI, 3.89-37.3), significant objective SCORAD score decreases of 56.8% and 34.9% in HDM SLIT and placebo groups (mean difference, 21.3; 95% CI, 0.66-41.81), and more patients with Investigator's Global Assessment 0/1 in the HDM SLIT group as compared with the placebo group (14 of 35 vs 5 of 31; relative risk, 2.63; 95% CI, 1.09-6.39) were observed at 18 months.

Conclusions: Our results suggest that HDM SLIT may be effective in HDM-sensitized patients as an add-on treatment for atopic dermatitis.

Keywords: Allergen immunotherapy; Atopic dermatitis; House dust mite; Investigator’s Global Assessment; SCORing Atopic Dermatitis; Sublingual immunotherapy.