Environmental exposure to peanut and the risk of an allergic reaction

To review the evidence of the risk of environmental exposure to peanut to a peanut allergic individual.

A narrative review was performed using a PubMed search of relevant articles involving peanut environmental distribution, environmental peanut abatement, and public policy regarding peanut restriction.

Data from 4 studies have shown that peanut butter vapors and smeared peanut butter on skin do not cause systemic reactions, that peanut can be abated from hands and surfaces using appropriate cleaning agents, and that shelled peanut dust does not become airborne. Studies have recently confirmed dose of 1.5 mg of peanut protein would be generally tolerated by approximately 95% of the peanut-allergic population based on objective symptoms in challenge-based studies, affirming earlier research. Restrictive policies that focus on bans (or restricted presence in certain areas) of peanuts or peanut-containing products in environments such as schools or on commercial aircraft are not backed by evidence that such measures work, which may raise an uncomfortable clash between accommodations that lack any medical evidence of necessity and a desire to provide measures that comfort our patients.

There is little risk posed from non-oral exposure to peanut in the environment, from casual contact, proximity, or inhalation. If 5% of the population may tolerate a threshold of approximately 1.5 mg of peanut protein, this may help liberate behavior and situational-decision making regarding the necessity of certain avoidances and restrictions. Continued work is needed to dispel myths about the mechanisms of how peanut may induce an allergic reaction.