Dust Mite Immunotherapy May Help Some With Eczema

Marcia Frellick

December 02, 2021

Sublingual immunotherapy (SLIT) with house dust mite (HDM) extract showed some benefit in improving the signs and symptoms of atopic dermatitis in mite-sensitized patients, but improvement in the primary outcome was not significant, new data show.

Results of a small, randomized, double-blind, placebo-controlled trial were published recently in The Journal of Allergy and Clinical Immunology: In Practice.

Lead author Sarah Sella Langer, MD, with the Department of Medicine, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, in Brazil, and colleagues say their results suggest HDM SLIT is safe and effective as an add-on treatment.

The dust mite extract therapy had no major side effects after 18 months of treatment, the authors report.

Researchers included data from 66 patients who completed the study. The participants were at least 3 years old, registered at least 15 on the SCORing Atopic Dermatitis (SCORAD) measure, and had a skin prick test and/or immunoglobulin E (IgE) test for sensitization to dust mites.

Patients were grouped by age (younger than 12 years or 12 years and older) to receive HDM SLIT (n = 35) or placebo (n = 31) 3 days a week for the study period -— between May 2018 and June 2020 — at the Clinical Research Unit of Ribeirão Preto Medical School Hospital.

At baseline, the mean SCORAD was 46.9 (range, 17 – 87).

After 18 months, 74.2% and 58% of patients in HDM SLIT and placebo groups, respectively, showed at least a15-point decrease in SCORAD (relative risk [RR], 1.28; 95% CI, 0.89 – 1.83). However, those primary outcome results did not reach statistical significance.

On the other hand, some secondary outcomes did show significant results.

At 95% CI, the researchers report significant objective-SCORAD decreases of 56.8% and 34.9% in HDM SLIT and placebo groups (average difference, 21.3). Significantly more patients had a score of 0 or 1 on the 5-point Investigator's Global Assessment scale in the intervention group than in the placebo group (14/35 vs 5/31; RR, 2.63).

There were no significant changes in the Eczema Area and Severity Index, the visual analogue scale for symptoms, the pruritus scale, or the Dermatology Life Quality Index.

Patients in the trial, most of whom had moderate to severe disease, continued to be treated with usual, individualized therapy for AD, in accordance with current guidelines and experts' recommendations.

Tina Sindher, MD, an allergist with the Sean N. Parker Center for Allergy and Asthma Research at Stanford University, in Stanford, California, told Medscape Medical News that the results are not robust enough to recommend the immunotherapy widely.

She pointed out that even in the placebo group, more than half the patients met the primary endpoint.

However, she did say HDM SLIT could be considered as an add-on treatment for the right patients, especially since risk for an allergic reaction or other adverse condition is small. The most common adverse effects were headache and abdominal pain, and they were reported in both the treatment and placebo groups.

With AD, she said, "there is no one drug that's right for everyone," because genetics and environment make the kind of symptoms and severity and duration different for each patient.

It all comes down to risk and benefits, she said.

She said if she had a patient with an environmental allergy who's trying to manage nasal congestion and also happened to have eczema, "I think they're a great candidate for sublingual dust mite therapy because then not only am I treating their nasal congestions, their other symptoms, it may also help their eczema," Sindher said.

Without those concurrent conditions, she said, the benefits of dust mite immunotherapy would not outweigh the risks or the potential burden on the patient of having to take the SLIT.

She said she would present the choice to the patient, and if other treatments haven't been successful and the patient wants to try it, she would be open to a trial period.

The study was supported by the Brazilian National Council for Scientific and Technological Development; the Institute of Investigation in Immunology, the National Institutes of Science and Technology, the Brazilian National Council for Scientific and Technological Development; and the São Paulo Research Foundation. The mite extract for immunotherapy was provided by the laboratory IPI-ASAC Brasil/ASAC Pharma Brasil. Langer received a doctoral scholarship from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES). Sindher reported no relevant financial relationships.

J Allergy Clin Immunol Pract. Published online November 9, 2021. Full text

Marcia Frellick is a freelance journalist based in Chicago. Follow her on Twitter at @mfrellick.

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