This was in today's Medscape:
Ask the Experts about Asthma
from Medscape Allergy & Clinical Immunology
Allergy to Peanuts and Peanut Products
Question
Is it possible, in children who are allergic to peanuts and peanut products, to have an allergic episode from simply being in the same room with these products? That is, from inhaling such as by simply breathing?
Charles Emich
Expert Response from James E. Gern, MD
Associate Professor of Pediatrics, University of Wisconsin Medical School, Madison
Peanut allergy is quite variable, and symptoms experienced by affected individuals can be quite mild, such as a few hives on the face, or severe, as in respiratory distress and cardiovascular compromise. Likewise, the amount of peanut protein that is required to cause a reaction is also quite variable. On one end of the spectrum, extremely sensitive individuals can react to milligram quantities of peanut protein, while others may tolerate several peanuts before initiating allergic symptoms. Those individuals who are extremely sensitive to low amounts of peanut protein can indeed have reactions to small amounts of peanut protein that become airborne. Examples of this phenomenon were brought to public attention a few years ago because of anecdotal reports that passengers who avoided ingestion of peanuts nonetheless experienced allergic reactions on commercial airliners that served roasted peanuts to other customers.[1]
Besides focusing attention on the airlines, this also prompted research as to whether casual contact with peanut butter in schools was a significant health hazard. Studies have demonstrated, however, that washing is an effective way to remove peanut protein from cafeteria tables.[2] In addition, cutaneous contact with peanut butter, as well as the smell of peanut butter, generally does not elicit systemic allergic reactions. In a study conducted by Simonte and colleagues,[3] 30 children with documented peanut allergy were challenged by applying peanut butter to a small area of skin. Although contact with the skin caused itching or a local skin reaction in some children, none had systemic reactions. In addition, none of the children reacted to a surface coated with peanut butter (the smell was disguised), when breathing for 10 minutes, 12 inches away from the surface. Although these results are comforting, it should be emphasized that other forms of peanut protein (shelling peanuts) could lead to aerosolization of peanut protein, and this could therefore represent a significant health hazard.
Posted 12/20/2004
References
1. Rayman RB. Peanut allergy in-flight. Aviat Space Environ Med. 2002;73:501-502. Abstract
2. Perry TT, Conover-Walker MK, Pomes A, Chapman MD, Wood RA. Distribution of peanut allergen in the environment. J Allergy Clin Immunol. 2004;113:973-976. Abstract
3. Simonte SJ, Ma S, Mofidi S, Sicherer SH. Relevance of casual contact with peanut butter in children with peanut allergy. J Allergy Clin Immunol. 2003;112:180-182. Abstract
Disclosure: James E. Gern, MD, has disclosed that he has received grants for clinical research from GlaxoSmithKline and grants for educational activities from MedImmune. He is on the speaker's bureau for Merck, Inc.
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Medscape Allergy & Clinical Immunology 4(2), 2004.
