Allergists Can Take the Worry Out of Peanut Allergies with Food Sublingual Immunotherapy
Allergy & Asthma Specialists offer answers to ease anxiety about the procedure.
Peanut extract drops are placed under the tongue to decrease the risk of serious reactions with accidental exposure to peanuts.
What is sublingual immunotherapy?
Sublingual immunotherapy is a process that reduces a person’s reactivity to an allergen. A dosage of the food extract is placed under the patient’s tongue, held there for 2 minutes, and then swallowed. Over time, the dose is gradually escalated so that the patient can tolerate more of the food with a decreased likelihood for an allergic reaction. Patients must be able to hold drops under their tongue for 2 minutes before swallowing to be successful candidates for sublingual immunotherapy. Most children 5 years and older can master this technique.
1. Is SLIT a cure for food allergy?
Not really. Studies of SLIT for foods show that SLIT can significantly increase the amount of food a patient can tolerate without having an allergic reaction. One study showed that peanut allergic patients who underwent SLIT for peanut were able to tolerate almost 7 peanuts before having a reaction, compared to less than 1 peanut for patients who were treated with a placebo. While not a cure, this effect is life altering as it may mean the difference between tolerating an accidental ingestion instead of having an anaphylactic reaction. It is not yet known if SLIT for foods is able to induce long term tolerance of the food.
2. Is SLIT safe?
In general, SLIT for foods is safe. In the published studies of SLIT for foods, systemic allergic reactions were quite rare, less than 1%. In one large study, 12 reactions were seen in 4,182 active doses. 11 of these reactions were mild and required treatment with an oral antihistamine only. 1 reaction required a nebulized medication for wheezing. None required administration of Epinephrine. However, because we are administering protein of a food that the patient is allergic to, it must be done very carefully with supervision by our allergists.
3. What is the difference between SLIT and oral immunotherapy (OIT)?
Oral immunotherapy is a process by which increasing amounts of an allergenic food (mixed into a safe food) are fed to an allergic individual. However, while promising, several studies of this treatment have shown an unacceptably high rate of severe allergic reactions. Approximately 50% of patients in these studies dropped out due to anaphylactic reactions. OIT is still being actively studied, and we may offer it in the future when the research protocols are further refined. It is not known if OIT for foods is able to induce long term cure of the allergy.
4. How does SLIT for food work?
SLIT for food is a process that takes 6-8 months. At the first visit, a small amount of extract will be placed under the patient’s tongue, held for 2 minutes and then swallowed. The patient will be observed in the office for 2 hours to make sure the dose is tolerated. The patient will then take this same dose daily at home for 2 weeks. At the end of 2 weeks, the patient will come back for a dose escalation visit where a larger dose will be given. The patient will be observed for another 2 hours. They will then take the larger dose at home daily for 2 weeks. The dose will be increased every 2 weeks until a maximum or “maintenance” dose is achieved. Typically, the maintenance dose is achieved in 6-8 months.
5. Do I need to stop my allergy or asthma medications for SLIT dosing in the office?
No, it is critically important that you continue to take all of your medications exactly as prescribed by your allergist. Failure to do so may make us unable to continue you on SLIT for foods.
6. How often is the dose increased?
The dose is increased every 2 weeks with a 2-3 hour “dose escalation” visit in our office.
7. What time of day should the home doses be given?
If the patient is a child, it should be given at a time when there is appropriate parental supervision, and at least 2 hours before bedtime. If the patient is an adult, it is best to give the dose when another responsible adult is around and available. No food may be eaten 15 minutes before the dose and 30 minutes after the dose. Injectable epinephrine, oral antihistamines, and asthma medication (if applicable) must be available when the dose is given. The patient may not exercise for 2 hours after the dose is given. Once the maintenance dose is reached, the patient may exercise 1 hour after dosing. These guidelines exist for your safety! Failure to rigorously adhere to these guidelines may make us unable to continue your SLIT.
8. How long should I/my child stay awake after the dose?
The dose should be given at a time at least 2 hours prior to bedtime or nap.
9. Should I give my home dose on the day of a “dose escalation” visit?
No, please do not give the home dose on the day of a “dose escalation” visit.
10. What do I do if I miss my “dose escalation” visit?
If you have to miss the dose escalation visit for any reason, please continue your current daily dose, and reschedule your dose escalation visit as soon as possible.
11. If there is a reaction at home, what should I do?
Treat the reaction exactly as you would a regular food reaction. All food allergy patients should have an active Anaphylaxis Management Plan. If the reaction is a rash only, an appropriate dose of Benadryl should be given. If there are any other symptoms of anaphylaxis, injectable Epinephrine should be given in addition to Benadryl, and you should call 911 or take the patient to the nearest ER (whichever you believe will be faster). If you are experiencing a reaction yourself and nobody is present to drive you, after taking the appropriate medications, unlock your door and call 911.
12. What should I do if I miss a home dose of my SLIT?
If it has been less than 48 hours since the previous dose, please administer the dose immediately. However, if it has been more than 48 hours, please contact our office and do not administer the dose.
13. Does the SLIT solution (“extract”) need refrigeration?
14. What should I do if I forget to refrigerate the extract?
If the extract sits out for more than 24 hours, please refrigerate immediately and call us for advice.
15. What if I/my child is sick?
If you/your child is sick with an asthma exacerbation, the dose should not be given and please call us for advice. Also, if you have any ulcers or cuts in your mouth, do not give the dose and please call us.
16. What is the goal of SLIT for foods?
Right now, our goal is to safely decrease the chances of a reaction from an accidental exposure to an allergenic food. As further studies about SLIT and OIT for foods evolve, better strategies for achieving long term tolerance (i.e. a “cure”) may be found.
17. Do I need blood or skin tests during sublingual immunotherapy for foods?
No additional testing is needed during SLIT for foods.
18. How do I know if SLIT is working for me/my child?
We strongly recommend continued complete peanut avoidance, even after the maximum dose of peanut SLIT is achieved. You may discuss with your treating allergist the risks and benefits of doing an oral challenge for peanuts in the office once the maximum dose is achieved.
19. What is the follow up schedule after the maintenance dose is achieved?
After the maintenance, or maximum, dose is achieved, you will be seen at two weeks, one month, and three months to make sure things are going well.
20. Will SLIT be covered by my insurance?
All insurers and policies are different. Because this is a new treatment, we recommend checking with your insurance provider directly. We anticipate that the dose escalation visits should be covered (copayments, deductibles and coinsurances will apply as per your insurance plan) and will be billed as “rapid desensitization”. We do not believe that the insurers will pay for the peanut extract because this procedure is considered an “off-label” use of the extract. In other words, the extract is FDA approved for allergy testing, but not yet for SLIT. The charge for the SLIT extract is $180 for a six month supply payable prior to starting food immunotherapy.