Sublingual Immunotherapy (SLIT)
What Is SLIT?
Sublingual immunotherapyis an alternative way to treat allergies without injections. An allergist gives a patient small doses of an allergen under the tongue to boost tolerance to the substance and reduce symptoms. According to a 2009 World Allergy Organization (WAO) paper, SLIT is widely accepted and used in European, South American, and Asian countries as well as in Australia and is gaining interest from allergists in the United States. However, as neither the safety nor the efficacy of the procedure is as yet considered established by the FDA, SLIT is not approved in the United States and its usage is off-label. However, trials for FDA registration are ongoing, with aspects of therapy including best dose and treatment duration, lasting effect and the exact way SLIT works are all under investigation.
How Is Treatment Administered?
An allergist must first use allergy testing to confirm the patients sensitivities. Once this is determined, an allergen extract is prepared in drop or tablet form and the patient is directed to keep it under the tongue for one to two minutes and then swallow it. The process is repeated from three days a week to as often as daily with recommendations that therapy is continued for three to five years to develop a lasting immunity.
Is Sublingual Immunotherapy Effective and Safe?
Most clinical trials and surveys published over at least 20 years show that SLIT is relatively safe and effective for the treatment of rhinitis and asthma caused by allergies to dust mites, grass, ragweed, cat dander, and tree pollens. As of June 2009, of 60 double-blind, placebo-controlled studies of SLIT, 48 trials showed positive results and 12 showed results that were totally or almost totally negative, according to the WAO paper. Evidence is emerging that SLIT may be effective for treating the red, itchy eyes caused by pollen during hay fever season.
In addition, it might prove an effective therapy for children with mild atopic dermatitis (eczema)and is currently being studied for its potential in treating food allergies.
Side effects among both children and adults are usually local and mild, most often occur early in treatment, and include itching in the mouth or stomach problems. These can usually be managed by dose adjustments. International studies reveal that SLIT can be safe for children under age 5 and may be a preferred method for controlling allergy symptoms compared with injection therapy.Very rarely, severe allergic reactions (anaphylaxis) have been reported using SLIT. Therefore this treatment is best prescribed by an allergist.
What Are the Risks of Sublingual Immunotherapy?
For the most part, SLIT risks relate to the nature of the treatment: it is administered at home and without direct medical supervision. Patients should therefore receive clear guidance from allergists on managing adverse reactions and treatment interruptions and should know when to consult the prescribing allergist.
Learn more about this therapy and get relief by consulting with an allergist.