Peanut allergies have become a major health concern in the United States. Peanuts are one of the most common causes of food allergies and along with tree nuts they account for most of the cases of fatal and near-fatal anaphylactic reactions to food. Not only is there a rise in the prevalence of peanut allergies in Westernized countries but also most patients with peanut allergies have lifelong clinical sensitivities to peanuts. Patient management involves strict avoidance, recognition of the early symptoms of anaphylaxis, and usage of an emergency treatment plan, including the self-administration of epinephrine in case of an accidental ingestion. Future treatment strategies may include recombinant peanut protein immunotherapy and anti-Immunoglobulin E therapy to modulate clinical reactivity to peanuts. This article reviews the current understanding of the clinical characteristics, pathogenesis, diagnosis, and management of the peanut allergy.