MED Allergies swelling, doctors baffled
By Jeremy Olson
Knight Ridder Newspapers
"Don't eat that" remains the best advice doctors can give to people suffering from food allergies.
There are no therapies -- no shots, no pills -- specifically marketed to treat food allergies, which appear to be on the rise in the United States. By one estimate, the rate has doubled in 20 years.
While doctors are exploring new remedies, unique ethical, business and safety barriers hinder their research, especially when children are involved. They also don't understand why food allergies are becoming more prevalent, though they have theories.
Take peanut allergies, which are among the most potent and deadly food allergies. Maybe children develop allergies by eating too many peanut products as infants, or through breast milk. Maybe roasted peanuts explain America's problem, because countries that fry or boil nuts have lower rates. Maybe the increase in peanut allergies reflects the increase in all allergies -- from pollen to pets to peanuts.
All of the explanations have flaws, said Dr. Scott Sicherer of the Jaffe Food Allergy Institute in New York's Mount Sinai School of Medicine. He supports the "hygiene" theory that Americans live such clean, antibiotic lives that their immune systems are finding something else to attack -- the proteins in certain foods.
The immune system gets "misdirected," Sicherer said. "It is not getting the practice that it needs to."
The compelling evidence is the lower allergy rate in undeveloped countries, where people's immune systems are busy fighting off bacteria, viruses, water contaminants and other pollutants.
If true, the hygiene theory presents a public health dilemma. America isn't going to revert to dirty conditions to prevent allergies. And yet food allergies present dangers, including anaphylactic shock, that kill as many as 150 to 200 people each year.
Roughly 4 million Americans have true food allergies, which involve the immune system's reaction to food proteins. Allergies are distinct from milder cases of food intolerance, which are often temporary.
One positive result, physicians said, is the growing public awareness.
Even without a wonder drug, Sicherer said, doctors provide meaningful care by teaching patients to avoid certain foods and hidden ingredients. "Education," he said, "is a treatment, in my book."
Researchers are testing experimental drugs for food allergies, but the cruel twist is they must expose people to the allergens in order to know whether the drugs work.
A national study based in Denver was marred by the death of a child who mistakenly received an experimental treatment, which contained peanut extract, instead of a traditional allergy injection without the extract. The idea was to desensitize people with peanut allergies by exposing them to the extract in a rapid series of doses.
"The difficulty with food allergies is these people have fairly violent degrees of reactivity," said Dr. John Yunginger, whose team at the Mayo Clinic helped investigate the child's death and verified the error.