When botanist George Washington Carver proposed 300 new uses for the peanut, he couldn't have foreseen enriched cocoa, Kung Pao chicken and pine-cone bird feeders.
Today, scientists say the ubiquity of peanuts has contributed to a surprising upswing in allergic reactions that can kill -- symptoms that can escalate from itching and wheezing to outright choking.
The peanut is so powerful an allergen that some people can't tolerate any food that has shared the same counter top with a peanut butter sandwich. In restaurants, people question chefs to make sure that dishes as innocent as filet mignon are untainted.
"A man died a year and a half ago -- his egg roll had been glued shut with peanut butter," said Anne Munoz-Furlong, founder of the Food Allergy Network, a consumer group based in Fairfax, Va.
Two Massachusetts schools and an entire school district in London, Ontario, have banned peanuts from cafeterias. Elsewhere, other schools have taken lesser steps. The McDonogh School in Owings Mills, for instance, is keeping peanuts out of its prepared lunches and desserts.
Allergic children are learning to scrutinize the ingredients on snack food packages before daring to take a bite.
"No matter where he goes, he has to read labels," said Julie Finkelstein of Owings Mills, whose son Andrew, 8, attends McDonogh. "Peanuts may be the 10th or 15th ingredient. It's something he has to think about all the time."
Food allergists, led by Dr. Hugh A. Sampson of the Johns Hopkins Medical Institutions, are trying to answer perplexing questions about the peanut, a legume that grows underground. For instance, what are the specific proteins that make some people sick? The answer could lead to a cure -- even to a genetically engineered peanut that's as benign as lettuce.
Another puzzle is the recent rise in cases. Peanuts have been a staple of the American diet for much of the 20th century, but only in the last decade have they become a common health problem among youngsters.
Scientists also want to know why children outgrow allergies to eggs and cow's milk by the time they are 3, but rarely lose their sensitivity to peanuts. They also wonder why other legumes, such as peas and beans, rarely cause life-threatening reactions.
Just as mysterious is the peanut's potency: Some people can't even tolerate its aroma.
