Sublingual immunotherapy: effect on drug use, but not on symptoms

Sublingual immunotherapy reduces the use of rescue medication in children allergic to grass pollen but not the symptoms of rhinoconjunctivitis, suggests a German trial published in the specialized "Allergy" journal.

This treatment is to desensitize the patient, that is to say, to inhibit the excessive reactivity of the immune system responsible for the crisis, exposing to increasing doses of (or) allergen (s) implicated (s).

Compared to the desensitization subcutaneously (mode of administration of the allergen which was initially based on the treatment of allergy immunotherapy), sublingual immunotherapy (which is kept under the tongue for two minutes a piece of sugar which was poured a few drops of a solution of allergen) offers advantages, especially in children. Indeed, it is well tolerated and promotes compliance, explain Claudia Rolinck-Werninghaus, Humboldt University in Berlin, and colleagues.

However, only few trials have been conducted to evaluate sublingual immunotherapy rigorously, and they have yielded conflicting results.

German researchers have conducted an analysis attended for nearly three years, 97 children with allergic rhinoconjunctivitis to grass pollen.

Some of the young participants, aged 3-14 years at the start of the study, received sublingual immunotherapy against five grasses, while others received a placebo, and without that neither children nor the researchers know if the product contained or not administered allergens.

Symptoms and consumption of rescue medication (eye drops, nasal decongestant, antihistamine systemic, intranasal corticosteroids and / or inhaled beta-2-agonist bronchodilator) were evaluated daily during the pollen season before inclusion and after a year and Finally, after three years of treatment.

The results show that after about three years of treatment, sublingual immunotherapy is not significantly reduced the symptoms of rhinoconjunctivitis compared to placebo.

However, it is accompanied by a significant drop in the use of rescue medication, marked by a reduction of about 67% of the score reflecting the drug consumption compared to placebo.

The results of diagnostic tests for allergies (specific IgE, skin tests, provocation tests) were in turn found to be comparable between the two groups, the authors say.

Sublingual immunotherapy was generally well tolerated. A single case of serious adverse events was observed, a severe asthma requiring hospitalization.

These results indicate that long-term treatment with sublingual immunotherapy of allergic rhinoconjunctivitis in children with or without asthma reduced the use of rescue medication, but has no significant effect on the symptoms.

Further studies are needed before recommending sublingual immunotherapy as an alternative treatment to the subcutaneous route, the authors conclude.