For millions of people with food allergies, every trip seems like adventure travel. Like mountain climbers and trekkers, they must have their own gear and rely on themselves to cope with risks that may prove life-threatening.
"It's like Russian roulette," said Jamie Hintzke of California. "You've got to be super careful."
The challenges can be formidable, but they needn't keep sufferers from leaving home, doctors and travelers say. They just have to prepare.
Hintzke, whose 12-year-old son, Max, is severely allergic to peanuts and tree nuts - an increasing number of children have such allergies - wipes down armrests, tray tables and audio-control buttons before Max takes his seat on a plane.
She quizzes restaurants about ingredients and food preparation. At hotels, mother and son take their own soaps (some brands are made with nut oils), and Max skips the chocolate on the pillow, which might contain nuts.
"We don't touch doorknobs," Hintzke said. "We don't touch railings."
Despite these precautions, she said, Max once broke out in hives when fellow passengers opened packages of macadamia nuts on a flight from Hawaii.
The Hintzkes always carry medications when they travel, including epinephrine, which can counter allergic reactions. And travel they do, including trips to London, Denver and Walt Disney World in Florida.
"It is a lot of work, and I suppose we are tempting fate," Hintzke said. "But we have decided not to live life fearing the 'what if.'"
Catherine Watson of Minneapolis, who is severely allergic to peanuts, also is not deterred.
She still works as a freelance travel writer despite twice detouring to emergency rooms last year after ingesting unexpected peanut bits in beef stroganoff at a Los Angeles restaurant and in vanilla ice cream on a stop while driving home from Illinois.
Among Watson's rules of the road:
"I don't eat anything on airplanes, even trans-Atlantic travel," she said.
And in restaurants she presents the staff with a laminated note card that displays a peanut with an "X" across it that says in several languages: "Do not give me peanuts. I will die."
About 12 million Americans are thought to have food allergies, said Dr. Scott Sicherer, associate professor of pediatrics at Mount Sinai School of Medicine in New York and author of Understanding and Managing Your Child's Food Allergies.
Although many foods may trigger allergies, Sicherer said, peanuts, tree nuts (such as walnuts and Brazil nuts), fish and shellfish tend to cause the most severe reactions, including anaphylaxis, which disrupts breathing and circulation and can be fatal.
The incidence of peanut allergies in children, now about 1 in 125, doubled between 1997 and 2002, according to a study by Sicherer.
Eating half a peanut kernel can cause potentially life-threatening reactions, Sicherer said; for some people, eating smaller amounts or just breathing peanut dust can cause problems.
The food-allergic traveler has few legal allies.
The notion that airlines must provide "peanut-free" zones is an urban myth. No such federal law exists, said Bill Mosley, spokesman for the U.S. Department of Transportation.
In 1998, the agency proposed that U.S. airlines refrain from serving peanuts in the row where an allergic passenger sits, plus the row in front and the row behind, he said, but later that year Congress prohibited the DOT from enforcing such zones.
Federal law requires airlines to include epinephrine in onboard emergency medical kits, although doctors say patients with severe allergies should always travel with the loaded syringes.
The Transportation Security Administration allows passengers to bring syringes containing medication provided the item carries a manufacturer's label indentifying the contents.
Today, several airlines say they don't serve peanuts, among them American, JetBlue, Northwest, United and US Airways. But Continental, Delta and Southwest still do; policies vary.
If you notify Southwest of an allergy, for instance, it will serve pretzels instead of peanuts on your flight, spokeswoman Marilee McInnis said.
Continental does not do this.
"We do not set up a peanut-free zone," said Continental's Mary Clark. Such an action, she explained, would mislead customers into thinking the cabin is free of allergens, which the airline cannot guarantee.
Laws aren't much help in restaurants either.
Since last year, labels on packaged foods have been required to carry allergen information. But no federal regulation requires restaurant menus to list allergens, said Sheila Weiss, director of nutrition policy for the National Restaurant Association, based in Washington.
The restaurant group opposes menu labeling, Weiss said, because it would provide a "false sense of security" and might discourage diners from telling staff about their allergies. Ingredients change, she noted, and cross-contamination can occur.
But the association views allergies as an important issue, she said, and works to educate members about dealing with them.
If customers inquire, "every ingredient that is known should be disclosed," Weiss said, and extra care should be taken with cleaning utensils and surfaces that have been used for allergenic foods.
Despite the difficulty of traveling with food allergies, Sicherer said, "I wouldn't want my patients to stay home because of this concern."
Talk to your allergist about precautions, he advised, and be assertive about telling waiters, airlines and hotels about your needs. The Food Allergy & Anaphylaxis Network posts useful travel tips on its Web site, food allergy.org.
Jane Engle writes for the Los Angeles Times.