Sublingual Immunotherapy (SLIT) for Food Allergy

Sublingual (i.e. under the tongue) immunotherapy (abbreviated SLIT) is a method of treating allergies in patients who are sensitized to certain pollens, dust, or foods. Only SLIT tablets to treat specific pollen or dust mite allergens are approved by the FDA. SLIT addressing food allergies is NOT approved by the FDA. This method involves putting drops of a solution containing a mixture of glycerin and the allergenic food under the tongue. It is held there for two minutes then swallowed. Doses are administered every day at home. They are increased in the office under supervision every several weeks until maintenance doses are reached.

The solutions for SLIT are a food product, so FDA approval is only necessary if a company wants to market a specific, proprietary product.

To be eligible for SLIT, you must have IgE mediated food allergies as diagnosed by history of reaction, and/or skin testing or blood work. In addition, you must be able to adhere to daily dosing, as improper adherence to the protocol can result in significant and serious adverse effects.

• The food solution contains food proteins that come in contact with immune cells (dendritic cells) in the oral mucosa that communicate with other immune cells (T lymphocytes) to hyposensitize the patient, or reduce their allergies.

We treat the many of the same kind of food allergies with SLIT that we also treat with OIT – peanut, tree nuts, milk, egg, sesame, and wheat.

The current standard of care for food allergy treatment is strict avoidance. Another method currently offered by a growing number of allergists is oral immunotherapy (OIT).  There is a peanut capsule that has been approved by the FDA for OIT.  Other methods, such as epicutaneous immunotherapy, are currently being researched and not available to the public.

• Allergen immunotherapy (of any type) changes your underlying immune response to the allergen in question, essentially teaching your immune system tolerate it.
• The goal of SLIT is NOT to allow for free-eating of the allergenic food.

• SLIT has several advantages and disadvantages compared to OIT.
• Advantages:
  • Safety – There is a low risk for serious, “whole body” allergic reactions (i.e. anaphylaxis)
  • Convenience – SLIT does not require the same duration of rest time following doses (1 hour compared to 2 hours).
  • Administration – Doses are lower in volume compared to OIT, which can be more easily administered and tolerated.
  • Taste—The glycerin gives the drops a sweet taste, so taste aversion is less of a concern. This can also alleviate the psychological burden of sensing (smell/taste) an allergenic food the patient has been conditioned to avoid.
  • Ease and safety make SLIT an attractive alternative to OIT for patients who are highly allergic, those who have struggled with OIT in the past, teens or adult patients.
• Disadvantages:
  • Overall protection – SLIT doses are not increased to a level that would be considered safe for “free eating” of the allergenic food.
  • Administration – Doses should be held under the tongue for several minutes, which can be more difficult for younger patient.

Each day, you put the solution under yr tongue and hold it there for 1-2 minutes, then swallow. You should not eat or drink anything for at least 5 minutes following administration. There is an activity restriction for 1 hour following administration.

• • The first doses/increased doses of the solution are administered under supervision in the office.

The safety of SLIT has been well documented over the past few decades. Serious reactions are extremely rare.  The oral mucosa, where SLIT presents the allergenic food, is well condition to tolerate various proteins on a daily basis, such as foods and resident bacteria.  There are few pro-inflammatory cells (called mast cells) which trigger allergic reaction sin the skin, nose, and lungs.

• You should refrain from vigorous activity for 15 minutes prior and 1 hour following dosing.
• You should also not eat or drink anything at least 5 minutes following administration.

• You should refrain from vigorous activity for 15 minutes prior and 1 hour following dosing.
• You should also not eat or drink anything at least 5 minutes following administration.

Whole body, systemic allergic reactions are extremely rare with SLIT, but possible. You will still be required to have an epinephrine autoinjector on hand.

Allergic inflammation of the esophagus, called eosinophilic esophagitis, is uncommon, but possible. Signs of this include pain the mid chest that doesn’t get better with medicines for acid reflux, or pain or difficulty with swallowing.  If SLIT is stopped, this condition usually resolves.

It may take up to a year of dosing for food SLIT to start working. You will need to continue to strictly avoid the allergen outside of the daily dose.

• Stop taking doses if you have major dental work that involves cutting the gums or pulling a tooth, any other injuries to the mouth, or inflammation in the mouth.  This is necessary because the allergen can enter the blood stream too quickly if the lining of the mouth is not intact.  These situation should be discussed with the provider.
• Illness may be another reason to skip your SLIT dose. Any concerns should be discussed with the provider.

It is possible to receive SLIT for more than one allergen.  In this case, the treatments are given sequentially, about 2-5 minutes apart.

• The desensitization appointments where your doses are initiated/increased will take about 2-3 hours. The patient may not eat or drink during dosing time.
  • The patient should not take a dose at home on the day they are scheduled for a dose increase or a challenge.
• Initial visits and follow-up visits will take about 30-60 minutes.

Yes, the solution must be refrigerated for palatability and prolongation of expiration.

• Foods that are available in a convenient, liquid form from the grocery store – milk, egg, and tree nuts – the maintenance doses will be undiluted food from your local grocery store. You will no longer be reliant on the office for solutions after the first 4 SLIT desensitization visits.
• For other foods – peanut, wheat, and sesame – we will provide solutions throughout maintenance in a 3 month supply at a time.

Any missed doses should be discussed with the provider.

Solutions are good for 3 months if kept in the refrigerator.