Perry TT, Conover-Walker MK, Pomes A, Chapman MD, Wood RA. J Allergy Clin Immunol. 2004;113:973–976
Purpose of the Study.
To determine the amount of peanut protein detectable in a variety of common exposure settings and examine the effectiveness of measures used to clean peanut from tables and hands.
A monoclonal-based enzyme-linked immunosorbent assay was used to detect 1 of the major peanut proteins (Ara h1) from surface-wipe samples of hands, tables, and other surfaces and from air samples.
After purposeful handling of a teaspoon of peanut butter, hand-washing with liquid soap, bar soap, or commercial wipes resulted in no detectable Ara h1. However, using plain water without soap or an antibacterial hand sanitizer left detectable Ara h1 on 3 of 12 and 6 of 12 hands, respectively. Purposeful placement of a teaspoon of peanut butter on 1 square foot of tabletop followed by cleaning resulted in no detectable Ara h1 when common household cleaning agents (such as Formula 409 or even plain water) were used; however, dishwashing liquid left Ara h1 on 4 of 12 tables (possibly by leaving a film). Six schools were assessed without special prior preparation (2 used peanut-free tables/preparation areas, and 1 was totally peanut-free). Of the 6 preschools and schools evaluated, Ara h1 was found on 1 of 13 water fountains (130 ng/mL), 0 of 22 desks, and 0 of 36 cafeteria tables. Airborne Ara h1 was undetectable in simulated real-life situations when participants consumed peanut butter, shelled peanuts, and unshelled peanuts.
The major peanut allergen, Ara h1, is relatively easily cleaned from hands and tabletops with common cleaning agents and does not seem to be widely distributed in preschools and schools. Airborne Ara h1 was not detectable in many simulated environments.
A major concern for those with peanut allergy is the potential for reactions to casual contact. This study is reassuring in that areas tested without obvious peanut contamination generally had no detectable Ara h1, and eating surfaces and hands, purposefully smeared with peanut, were cleaned adequately with simple, available methods. A limitation of the study is that the assay detected only 1 of several peanut allergens, so the total amount of peanut allergen on these items is unknown. Nonetheless, in most cases no peanut was detectable, providing a level of reassurance for families. On the other hand, it is known that a very small amount (although typically a visible amount) of peanut, if ingested, could cause a severe reaction in some children. Therefore, caution would still be advised about exposure to peanut and the need for careful cleaning practices, particularly with young peanut-allergic children. These children may be around messy eaters and may be inclined to place contaminated fingers and other objects into their mouths.