An experimental therapy used at a La Crosse clinic for almost three decades has been shown to significantly curb children's responses to peanut allergies.
A recent Duke University study shows that sublingual immunotherapy, or drops under the tongue, which have been used at Allergy Associates of La Crosse for years, are safe and could provide some relief for patients.
The double-blind, placebo-controlled study is the first of its kind on peanut allergies in the U.S. It found that allergy drops safely induced desensitization in children with peanut allergies and suggested a significant change in allergic response.
In the study, children treated with drops could tolerate the equivalent of six or seven peanuts before reacting, while the placebo group typically got a reaction with less than a peanut. Most accidental exposures for those with allergies is less than six peanuts.
People can experience life-threatening reactions such anaphylactic shock when they accidentally eat foods containing peanuts.
"I wasn't surprised by the differences in the two groups, but the significance of differences," said Dr. Wesley Burks, an allergist and lead study researcher at Duke. "Perhaps we can protect children against accidental ingestion."
Even though the drops have been experimental, Dr. David Morris and Allergy and Associates of La Crosse have used the therapy for years to treat hundreds of patients for food allergies.
Dr. Mary Morris, a physician with Allergy Associates, said some European studies had shown the effectiveness and safety of sublingual immunotherapy.
Mary Morris approached Duke about a study several years ago, and helped develop a safe dosing protocol for research based on the clinic's experience.
"It is very encouraging to see that in a double-blind placebo-controlled study, sublingual immunotherapy did increase the threshold of peanut required to be ingested before reacting," Morris said.
"This is an exciting area, which certainly suggests that we may have a specific treatment which will be more widely accepted over the next couple of years," she said.
The Duke research, recently published in the Journal of Allergy and Clinical Immunology, used a more aggressive dose escalation in hopes of children being able to ingest a larger amount of peanuts, Morris said.
"We should be more comfortable being more aggressive in treatment because the safety profile is good," Morris said.
Burks, the Duke researcher, said peanut allergy was chosen for the study because it is the most serious and sensitive food allergy.
"We can assume we would get the same results from sublingual immuno-therapy with other food allergies," Burks said.
"The allergy community can take away some optimism from this study that there could be treatments for peanut allergy and other food allergies on the horizon," he said.
Burks said he is planning another study to determine if sublingual immunotherapy can have a long-lasting effect.
He said the allergy community has been skeptical about allergy drops, but he became interested in the novel treatment.
"I think we try to be open minded about treatment," Burke said. "That's why we design studies to understand whether a treatment works and is safe."
In La Crosse, Morris said the Duke study has prompted Allergy Associates to conduct a small study among its peanut allergy patients.
"As always, the goal of treatment is to balance safety and efficacy," Morris said. "Our current approach with our clinic's sublingual immunotherapy treatment protocol for peanut allergy is very safe.
"Our current goal at the clinic is to decrease the risk of severe reactions with accidental exposure to peanut," she said.
Morris said more research has to be done before other clinics offer the therapy.
"We have the most experience than anyone, and our patients with peanut allergies have improved," Morris said. "But we have to continue to make sure treatment is safe and effective."