Food allergy: an enigmatic epidemic

• IgE clonality, reactivity to food components, and affinity are important criteria that determine immune reactivity.
• Food allergy is associated with Th2-skewed CD4+ T cells that express skin-homing markers.
• Genetic and environmental factors, such as diet and the intestinal microbiota, play a role in disease susceptibility.
• Immunotherapy, alone or combined with anti-IgE therapy might desensitize or tolerize to foods.

Food allergy is a common disease that is rapidly increasing in prevalence for reasons that remain unknown. Current research efforts are focused on understanding the immune basis of food allergy, identifying environmental factors that may contribute to its rising prevalence, and developing immunotherapeutic approaches to establish immune tolerance to foods. Technological advances such as peptide microarray and MHC class II tetramers have begun to provide a comprehensive profile of the immune response to foods. The burgeoning field of mucosal immunology has provided intriguing clues to the role of the diet and the microbiota as risk factors in the development of food allergy. The purpose of this review is to highlight significant gaps in our knowledge that need answers to stem the progression of this disorder that is reaching epidemic proportions.