Under Your Tongue

Some peanut allergies lessened with new treatment

(RxWiki News) Living with peanut allergies can be scary. Avoiding foods that might contain peanuts can be difficult but for those with severe reactions...one hidden nut can be life threatening.

A new immunotherapy treatment has been tested that might make peanuts safer for those with allergies.

"See your doctor if you have an allergic reaction."

Researchers exposed 40 people with peanut allergies to small amounts of peanut protein under their tongues to see if their tolerance for peanuts would improve over time.

After 44 weeks of daily treatment, 70 percent of the participants reduced their allergic reactions to peanuts. After 68 weeks, their reactions further decreased.

Exposing people to foods that cause them allergic reactions is very dangerous. Researchers advise that this type of treatment should only be done under direct supervision of a doctor.

The study, led by David M. Fleischer, MD, of the Department of Pediatrics at National Jewish Health in Denver, Colorado, aimed to find out how safe and effective it was to treat people with peanut allergies with sublingual immunotherapy.

Sublingual immunotherapy, known as SLIT, means giving patients the ingredient they are allergic to in very small amounts under their tongues. These small, repeated exposures allow some people to start tolerating what they are allergic to.

The researchers recruited 40 participants from five US cities all over the country. The participants were between 12 and 40 years old.

Each participant had a history of peanut allergy. However, none of the subjects had a history of severe allergic reactions to peanuts or moderate to severe asthma.

The research participants were told not to eat any peanuts or peanut products throughout the time of the study. They were also instructed to carry an epinephrine auto-injector with them.

To administer the SLIT study treatment, drops containing peanut protein were placed under the tongue. After two minutes the drops were swallowed.

At the beginning of the study the participants were given very low doses of peanut protein in the study clinics. Once the doctors giving the doses saw that they tolerated the dose level, they were sent home to repeat the treatment daily for two weeks.

At the end of the two weeks the participants returned to the clinic to get an increased level dose. This cycle repeated for 44 weeks.

All of their reactions to the study treatment were recorded on a daily basis.

At the end of the first 44 weeks of the study, 70 percent of the participants increased the average amount of peanut protein they could consume without a moderate or severe reaction from 3.5 milligrams to 496 milligrams.

At the end of 68 weeks of the study, the participants could tolerate eating even more peanut content. The average that subjects could tolerate increased to 996 milligrams of peanut protein.

It’s important to note that even with the low doses of peanut protein, many of the participants had some allergic reactions like itching in the mouth and throat.

Though most of the allergic reactions study participants experienced were mild, some were more serious.

After a daily dose at home, one patient developed very itchy red skin and more serious symptoms in the mouth. This individual recovered after an antihistamine, an epinephrine injection and close observation at one of the research centers.

An increased level of tolerance for peanuts for people with allergies means that they would be safer if they ate a peanut by accident. Accidental exposures usually happen when someone consumes 100 milligrams of peanut protein.

An average peanut has about 250 milligrams of peanut protein.

"Immunotherapy continues to show promise for treating food allergies," said lead author David Fleischer, MD, associate professor of pediatrics at National Jewish Health.

"But it is not yet ready for widespread use; there is a fine line between safely desensitizing patients and causing serious allergic reactions. We are still working to discover where that line is and how to select patients who would most likely benefit," he said.

The success of the SLIT method and other immunotherapy treatments like it would offer a proactive approach for people living with food allergies.

“Presently, food allergic patients are left to simply wait and hope that over time they will become tolerant to the food that they are allergic to,” said John Oppenheimer, MD, a pulmonary and allergy specialist and dailyRx Contributing Expert.

“With the exploration of food immunotherapy and possibly the sublingual route, it is hoped that we can take an active role in the ability to tolerate a food that one is allergic to,” he said.

“As stated by the authors, although not yet ready for prime-time, this study brings us hope and one step further to a potential cure,” said Dr. Oppenheimer.

The study was published in the January issue of The Journal of Allergy & Clinical Immunology.

The research was funded by the National Institutes of Health (NIH), National Institute of Allergy and Infectious Diseases (NIAID), the National Center for Research Resources (NCRR) and the National Center for Advancing Translational Sciences (National Jewish.)

Several of the study authors report potential conflicts of interest. Many have professional relationships with pharmaceutical companies, medical research publishing companies and other allergy and research-related organizations.

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Review Date: 
January 18, 2013
Last Updated:
January 20, 2013