Overview of Food Allergies in Children

Significance of Food Allergies

A recent review study examined the existing understanding of food allergies in children and the potential role of food immunotherapy as a widely accepted treatment option. Food allergies pose significant health risks, as even minute quantities of allergenic foods can trigger severe reactions. Between 1997 and 2011, research indicated a 50% rise in food allergies in the United States, with nearly 8% of American children affected.

Common Food Allergens

Allergies are provoked by allergens, which are primarily antigens found in proteins, but can also be present in certain carbohydrates and lipids. The most prevalent food allergens include milk, eggs, soy, wheat, peanuts, nuts, fish, and shellfish. Among children, cow’s milk, hen’s eggs, and peanuts are the leading causes of allergic reactions, with peanuts being the most frequent trigger for severe allergic responses, such as food-induced anaphylaxis.

Understanding Causes and Prevention

While some studies suggest that allergies to milk, eggs, soy, and wheat may be overcome, others indicate that certain allergies persist. The precise causes of food allergies remain unclear; however, researchers believe they may stem from a loss of oral tolerance or delayed development of this tolerance in early childhood. Early introduction of allergens may help prevent the onset of allergies.

Treatment Options for Food Allergies

Current Treatments

Presently, the most effective strategy for managing food allergies is the strict avoidance of allergens, coupled with immediate treatment for allergic reactions. Allergen immunotherapy has shown promise in treating pollen and insect venom allergies, and researchers are now exploring its efficacy and safety for food allergies in children.

Food Immunotherapy Explained

Food immunotherapy aims to raise an individual’s threshold of sensitivity to the allergenic food by administering gradually increasing doses of the allergen daily. This process, known as desensitization, seeks to achieve sustained unresponsiveness, allowing individuals to tolerate the allergen without experiencing allergic reactions after treatment cessation. According to an article published in April 2018 in the journal Children, the effectiveness of sustained unresponsiveness varies based on the immunotherapy route, which may be oral, sublingual, or epicutaneous.

Challenges in Treatment Protocols

Currently, there is no standardized treatment regimen for food immunotherapy, and protocols differ significantly across studies. Patients often experience mild to moderate side effects, with factors such as viral infections, menstrual cycles, and exercise potentially increasing the risk of adverse reactions. Individuals with histories of poor medication compliance, asthma, eczema, eosinophilic gastrointestinal diseases, or allergic rhinitis may not qualify for food immunotherapy.

Types of Food Immunotherapy

Oral Immunotherapy

Oral immunotherapy involves administering a small initial dose of the allergenic food (1-25 mg) daily over two to three weeks, with doses gradually increasing until reaching a maintenance level (300 mg to 4,000 mg) after six to twelve months. Approximately 70% of patients undergoing this therapy achieve desensitization, though mild to moderate adverse reactions, including oral itching and gastrointestinal symptoms, are common. Anaphylaxis may occur, particularly if doses are taken irregularly. Current applications include treatment for milk, egg, and peanut allergies in children, with studies showing that 50% of school-aged children and 75% of infants and toddlers achieve sustained unresponsiveness.

Sublingual Immunotherapy

Sublingual immunotherapy delivers the allergen in liquid form, held under the tongue for several minutes before swallowing. The initial doses are considerably lower than those used in oral immunotherapy, typically escalating to a maximum maintenance dose of 10 mg. Although this method is less effective than oral immunotherapy, it tends to cause milder and less frequent side effects, primarily localized to the oropharynx. Clinical trials for allergens such as milk, peanut, hazelnut, peach, and kiwi have shown minimal sustained unresponsiveness post-treatment.

Epicutaneous Immunotherapy

Epicutaneous immunotherapy involves applying an adhesive patch containing the allergen to the skin, typically on the back or inner arm, for 24 hours. Recommended fixed daily doses of 250 µg aim to achieve and maintain desensitization. Research indicates that 90% of participants experience mild local reactions, with a notable difference in response rates compared to placebo in studies involving children aged 6 to 11 with peanut allergies.

Conclusion

The exploration of oral, sublingual, and epicutaneous immunotherapy presents promising avenues for treating food allergies in children. As there is currently no cure for food allergies, the primary management strategy remains strict avoidance of allergenic foods and treatment of allergic reactions. It is crucial for healthcare professionals to be aware of these immunotherapy options and identify patients who may benefit, as they have the potential to significantly enhance the quality of life for affected individuals and their families.

Reference

Anvari S, Anagnostou K. The Nuts and Bolts of Food Immunotherapy: The Future of Food Allergy. Children. 2018, 5, 47.