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

BACKGROUND: Sensitization to house dust mites (HDM) is frequent in patients with atopic dermatitis (AD).

OBJECTIVE: To investigate the efficacy of sublingual immunotherapy (SLIT) with Dermatophagoides pteronyssinus(Dpt) extract in patients with AD sensitized to HDM.

METHODS: In this randomized, double-blind, placebo-controlled trial, we enrolled 91 patients aged ≥3 years, with SCORing Atopic Dermatitis (SCORAD) ≥15 and positive skin test and/or IgE to Dpt. Patients were stratified according to age (<12 and ≥12 years) to receive HDM SLIT or placebo for 18 months. Primary outcome was a >15-point decrease in SCORAD. Secondary outcomes were decreases in SCORAD and objective SCORAD (O-SCORAD), Eczema Area and Severity Index (EASI), visual analog scale (VAS) for symptoms, pruritus scale; Investigator's Global Assessment (IGA) 0/1; and decrease ≥4 points in Dermatology Life Quality Index (DLQI). 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% patients in HDM SLIT and placebo groups, respectively, showed >15-point decrease in SCORAD (relative risk[RR]1.28, 95% confidence interval[CI] 0.89-1.83). Significant SCORAD 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 O-SCORAD 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 IGA 0/1 in HDM SLIT group as compared to placebo group (14/35 vs 5/31;RR 2.63, 95%CI 1.09-6.39), were observed at 18 months.

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