Peanut allergy and anaphylaxis

Abstract

Peanuts are a frequent cause of food allergy and the most common cause of fatal food-induced anaphylaxis in the U.S. Advances during the past two years have promoted our understanding of peanut allergens and peanut allergy prevalence, etiology, diagnosis, and therapy. The advances highlighted in this review include evidence that the peanut allergens most important in disease differ in different parts of the world, that early oral exposure to peanuts may decrease the frequency of peanut allergy, while early nonoral exposure may have the opposite effect, that complement activation by peanut constituents appears to promote peanut-induced anaphylaxis and that oral immunotherapy, anti-IgE antibody, and a herbal formulation are promising approaches for the treatment of this disorder.

Figure 1. Peanut activation of complement exacerbates anaphylaxis

Peanut molecules activate complement, causing production of C3a, which acts through C3a receptors on mast cells, basophils and macrophages to induce production of PAF and histamine, which directly and indirectly increase vascular permeability and smooth muscle contractility.