February 12, 2015
TAKE-HOME MESSAGE
Emerging immunotherapies can be administered orally and have shown potential in the treatment of peanut, egg, and milk allergies. The authors describe the complexity of IgE-mediated allergies to food and summarize the therapies currently undergoing clinical trials.
Written by Benjamin Wright MD
Dramatic increases in the number of individuals with food allergies have fueled intense interest in the field of food allergy. This review focuses on the clinical diagnosis and management of food allergies and highlights several investigational therapies, including oral immunotherapy, sublingual immunotherapy, and epicutaneous immunotherapy. Although reasons for the rise in the prevalence of food allergy are not fully understood, some evidence suggests that cutaneous food antigen exposure coupled with skin barrier disruption (as seen in atopic dermatitis) may play a key role in food sensitization.
In recent years we, and others, have conducted large, controlled clinical trials investigating the efficacy and safety of oral and sublingual immunotherapy. It is clear that oral immunotherapy and, to a lesser extent, sublingual immunotherapy can induce desensitization in a majority of individuals with food allergy. However, only a small number of studies have systematically assessed tolerance. Food allergen immunotherapy has a number of limitations, including tolerability (eg, rhinitis and oropharyngeal and gastrointestinal symptoms) and adverse effects (eg, anaphylaxis and iatrogenic eosinophilic esophagitis). At this time, we cannot conclude that it confers significant advantages over avoidance of trigger foods.
Despite these limitations, immunotherapy may be a viable treatment option for food allergy in the future. Adjunctive agents such as omalizumab can shorten the escalation phase, decreasing the time period when most side effects occur. In addition, earlier intervention in younger patients may be more effective. Preclinical studies in animals are attempting to modify food antigens and delivery systems to improve safety while still retaining immunogenicity.
In summary, active therapies for food allergy remain investigational, although novel approaches may improve existing treatment modalities.
Abstract
Food allergies have increased in prevalence over the past 20 years, now becoming an important public health concern. Although there are no therapies currently available for routine clinical care, recent reports indicate that immunotherapies targeting the mucosal immune system may be effective. Oral immunotherapy is conducted by administering small, increasing amounts of food allergen; it has shown promise for desensitizing individuals with peanut, egg, or milk allergies. Sublingual immunotherapy also desensitizes allergic patients to foods-2 major studies have examined the effects of sublingual immunotherapy in subjects with peanut allergies. We review the complex nature of IgE-mediated food allergies and the therapies being evaluated in clinical trials. We focus on the diagnosis and management of food allergies, and investigational therapies.