Food
6:20 pm
Mon October 15, 2012

Experimental treatment for peanut allergies debated

Peanut allergies have been rising dramatically – enough so that many elementary classrooms have banned peanuts. About four times as many children have peanut allergies today as 20 years ago.

The severe form of peanut allergies can be deadly, which is why thousands of people must carry around an adrenaline shot (called an epinephrine pen, or "epi-pen").

Now, allergy doctors are debating whether they should offer an experimental allergy treatment. It was a topic this past weekend, at the 2012 Northwest Allergy Forum in Seattle.

Just a handful of doctors across the country have been offering Oral Immunotherapy Treatment (OIT). It’s similar in principle to immunotherapy treatment for hay fever and other allergies. That involves getting injections of the allergic substance and building up a tolerance.

However, the immunotherapy shots have never worked well for food allergies. One experiment with them in the 1990s was canceled after patients were having unacceptable reactions to the shots, including going into shock.

The difference with OIT is that you swallow a tiny dose of peanut protein, instead of getting an injection.

“A lot of people have asked about this for years. Every allergist gets this request,” says Dr. Jim Baker, an allergy doctor from Portland, who specializes in peanut allergies.

One doctor who says it's needed

Baker is the only doctor in the Pacific Northwest currently offering OIT -- and he reserves it for just the right type of patient. It can be dangerous (so don't try it at home, he says).

“I probably talk half of them out of it,” he says.

Baker has treated 86 patients, and he says 61 of them have successfully learned to tolerate peanuts. The other 25 had to stop the therapy for various reasons, ranging from abdominal pains to being unable to comply with the strict regimen.

The oral treatment is rigid, requiring two doses a day, at a precise hour every day. Those who succeed can now eat peanuts -- and have to keep eating peanuts every day, or the tolerance will wear off.

Baker started using the treatment about three years ago. Some colleagues in Texas were succeeding with it, and then researchers at Duke University completed an investigation that seemed to show promise.

“I started very, very slowly,” says Baker. “I was lucky that my initial patients came from physician families.”

With a physician at home, any bad reaction could be caught instantly, and the parents understood the seriousness of sticking religiously to the regime.

Most doctors want better evidence

Most allergists are not willing to offer OIT, yet. At the conference last weekend, Dr. Steve Tilles of Seattle offered a counterpoint. He says OIT is still too unproven.

“I don’t want to be prescribing something and keeping my fingers crossed that it does what I expect it to, in everyone,” says Tilles. “Maybe one out of 50, or one out of 100, has a horrible reaction.”

He compares it to going on a Boeing test flight of a brand new jet. It'll probably fly just fine the first time up, but most of us want to wait until after formal testing before we’re passengers. 

Baker counters that doctors can prevent bad outcomes by carefully managing their patients.

Allergy doctors expect clinical trials will happen in the next five years or so, showing exactly the risks and benefits of OIT. Until those results are in, most doctors, including national leaders, are telling people with peanut allergies they'll have to wait.

Currently, people with severe nut allergies can survive by being attentive and always carrying an epi-pen. About 125 people die each year in the US from severe reactions to peanuts, out of an estimated 3 million people with the allergy, said Tilles.

Although peanut allergies affect only about 1% of children under 18, many more parents think their children have a peanut allergy, based on getting a "false-positive" from a simple skin test. But, they have never seen a specialist to have that confirmed or denied, according to both Tilles and Baker.

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