Sublingual immunotherapy (SLIT) is as safe and effective for high-risk older children and adolescents as oral immunotherapy (OIT) is for infants and preschoolers, according to new research.
Preliminary data from a study of more than 180 pediatric patients with multiple food allergies showed that while most patients had mild symptoms, none experienced a severe grade 4 reaction during the buildup and maintenance phase of SLIT.
In addition, 70% of those tested at the end of the treatment protocol were able to tolerate 300 mg of their allergen, a success rate nearly as high as that for OIT.
The study was published in The Journal of Allergy and Clinical Immunology: In Practice.
SLIT has been used successfully in the treatment of environmental allergens such as grass and tree pollen and dust mites. In this study, researchers decided to test SLIT’s effectiveness and safety in the treatment of food allergies in older children.
“We knew that OIT is very effective and safe in infants and toddlers, but there was literature illustrating that for older, school-age kids and adolescents, OIT is not safe enough, as those older age groups tend to have higher risk of severe reaction during treatment,” senior author Edmond Chan, MD, clinical professor of allergy at the University of British Columbia and pediatric allergist at BC Children’s Hospital, both in Vancouver, British Columbia, Canada, told this news organization. “With that knowledge, we decided to explore SLIT as another first-phase therapy for the older kids.”
The investigators recruited 188 high-risk older children aged 4-18 years for multifood SLIT. Most (61.7%) participants had multiple food allergies. Approximately 68% were male, and the population’s median age was 11.3 years.
Nearly half (48.4%) of participants had atopic dermatitis, 45.2% had asthma, 58.0% had allergic rhinitis, and 2.66% had preexisting eosinophilic esophagitis.
Most (75.0%) of the children were classified as higher risk, and 23 had a history of a grade 3 or 4 reaction before beginning SLIT.
Of the 188 children who were initially enrolled in the study, 173 (92.0%) finished their SLIT buildup phase.
Because the study started when COVID-19 pandemic restrictions were in place, the SLIT protocol mandated that patients be seen virtually. The patients’ caregivers learned how to mix and administer the required doses at home using recipes specially developed by the research team that used products bought at the grocery store.
A wide variety of food allergens were treated, including peanut, other legumes, tree nuts, sesame, other seeds, egg, cow’s milk, fish, wheat, shrimp, and other allergens.
The children built up to 2-mg protein SLIT maintenance over the course of three to five visits under nurse supervision.
After 1-2 years of daily SLIT maintenance, patients were offered a low-dose oral food challenge (OFC; cumulative dose: 300 mg of protein) with the goal of bypassing OIT buildup.
Nearly all patients (93.1%) had symptoms during SLIT buildup, but most were mild grade 1 (52.1%) or 2 (40.4%) reactions. Only one patient had a grade 3 reaction. None of the patients experienced a severe grade 4 reaction.
The most common grade 1 reaction was oral itch, an expected symptom of SLIT, which occurred in 82.7% of the patients.
Four patients (2.10%) received epinephrine during buildup and went to the emergency department. All these patients returned to continue SLIT without further need for epinephrine.
To test the effectiveness of SLIT, the researchers performed 50 low-dose OFCs in 20 patients. Of these food challenges, 35 (70%) were successful, and patients were asked to start daily 300-mg OIT maintenance, thus bypassing OIT buildup.
An additional nine OFCs that were unsuccessful were counseled to self-escalate from 80 mg or higher to 300 mg at home with medical guidance as needed.
“Our preliminary data of 20 patients and 50 low-dose oral food challenges suggest that an initial phase of 1-2 years of 2-mg daily SLIT therapy may be a safe and effective way to bypass the OIT buildup phase without the need for dozens of in-person visits with an allergist,” said Dr. Chan.
“So now we have the best of both worlds. We harness the safety of SLIT for the first 1-2 years, with the effectiveness of OIT for the remainder of the treatment period,” he said.