Sublingual immunotherapy eases symptoms of dust mite allergy

Internal Medicine News, June 1, 2005

SAN ANTONIO -- Adults with dust mite allergy who are using standard allergy medications benefit from the addition of sublingual immunotherapy, according to Italian researchers.

"The clinical efficacy of sublingual immunotherapy has been previously established in pollen, but not dust mite allergy," said lead author Carlo Lombardi, M.D., who presented his research at the annual meeting of the American Academy of Allergy, Asthma, and Immunology.

Although the effect of sublingual immunotherapy is relatively easy to assess in pollen allergy, which has a fixed, seasonal occurrence, its effect on year-round dust mite allergy has been more difficult to assess, added Giovanni Passalacqua, M.D., a coauthor of the study.

But over a 3-year study period, the investigators observed a significant reduction in nasal obstruction, itching and cough, and a decreased need for symptom-relief medications in patients treated with standard medications plus sublingual immunotherapy, compared with those treated only with for allergic rhinitis and asthma.

The study randomized 68 patients with mild dust mite rhinitis and/or asthma to standard medication plus sublingual immunotherapy or standard medication plus placebo for 1 year.

Drug consumption and allergy symptom scores were tracked through diary cards, as well as the Short Form-36 Quality of Life Questionnaire.

Compared with patients receiving placebo, patients treated with sublingual immunotherapy experienced a significant reduction in symptoms. The treated group was also significantly less likely to report at least one missed day of work due to asthma (25% vs. 43%), Dr. Lombardi said.

There was no change in the quality of life in both groups, he said, adding that at baseline, all patients displayed a normal QOL profile. However, sublingual therapy patients reported an overall improvement in their change in health status,'" he said.

The study results are "revealing and important to the practice of allergy medicine worldwide," commented Clifford W. Bassett, M.D., medical director of Allergy & Asthma Care of New York.

Although sublingual immunotherapy has been a part of clinical practice in many parts of Europe for the past decade, and in Italy is used more commonly than the subcutaneous route of administration (70% vs. 30%), according to Dr. Passalacqua, it remains unapproved by the Food and Drug Administration.

"This and other research is fairly convincing that sublingual immunotherapy is effective when given correctly, at the proper dosage, and the right time. And its safety seems to be quite good from what we've seen so far," Dr. Bassett said.