(Circulation. 2000;101:e9006.)
© 2000 American Heart Association, Inc.
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Do Clean Hands Cause Allergies?
A group of Italian researchers claim that the increasing rates of allergic asthma and rhinitis stem from a decline in infections transmitted through the oral-fecal route and the diet of semisterile food eaten in Western countries.
Paolo Matricardi, MD, research director at the Laboratorio di Immunologia ed Allegologia, Divisione Aerea Studi Ricerche e Sperimentazioni in Rome, and his colleagues reported in the British Medical Journal that in a retrospective, case-controlled study of 240 military cadets with atopy (a predisposition to allergic reactions) and 240 without atopy, it seemed that those who had been heavily exposed to orofecal and food-borne microbes, such as Helicobacter pylori and the hepatitis A virus, were less likely to suffer from respiratory allergy and asthma than those who had been exposed to airborne viruses such as measles, mumps, and chickenpox.
The researchers concluded that "the decline of orofecal and food-borne infections and changes in the overall pattern of commensals and pathogens that stimulate gut-associated lymphoid tissue may be strong determinants of the epidemic of allergic rhinitis and asthma in developed countries. Although further studies are required to verify this conclusion, it is not inconceivable that we may soon use certain microbes or their molecules to prevent atopy without causing infectious disease" (BMJ. 2000;320:412–417).