Allergy, Food & Chemical Sensitivity Testing


Guidelines published by the National Institute for Allergy and Infectious Diseases conclude that neither blood nor skin tests are sufficient for making a diagnosis. However, some healthcare providers have found that combining the outcomes of these tests with elimination and elimination-challenge diets has helped interstitial cystitis (IC) patients to develop individualized IC diet plans. These modified meal patterns can help to control IC pain and flare-ups.

Urologist John Hubbard, MD, and allergist/immunologist C. Steven Smith, MD, from Louisville, Kentucky, are studying the link between allergies and IC. In addition to seasonal allergies, the team is finding that food allergies are also common in IC patients.

Dr. Smith estimates that 35 to 40 percent of IC patients he sees have bona fide allergies to foods, based on the results of their skin-prick tests and elimination-challenge diets. He found that their IC symptoms decrease when they remove those foods from their diets. Read more about this in the Spring 2009 issue of the ICA Update.

“If I eat something I’m allergic to, it bothers my IC. When I got a shot for tomato, which my regular food allergist found I tested positive for, it set off a flare so bad I started having to run to the bathroom every few minutes. The flare was severe and lasted for days.”
Linda
Baltimore, MD

Skin Tests

Some allergists don’t do skin-prick or intracutaneous (below the skin surface) tests for foods because they are concerned about the risk of anaphylactic shock which may occur when a test is administered for a food a patient may be highly allergic to. But, Dr. Smith pointed out, patients often know when they have a severe food allergy—their throat tightens and they may wheeze or get hives or other symptoms right after eating the offending food. “There’s no reason to test that patient. The history alone tells you what you need to know,” he said.

Dr. Smith is familiar with the IC diet study by Barbara Shorter, EdD, RD, CDN, Robert Moldwin, MD, and their colleagues at Long Island Jewish Medical Center in New Hyde Park, New York. And he is seeing interesting correlations between the allergies he is finding in his IC patients and the items that came up in this study as common symptom triggers.

The stimulants, such as coffee and tea, and the acid and spicy foods may be problems even without allergy. “Put those on already irritated bladder tissue and you probably are going to see a response,” Dr. Smith said. But he’s also finding allergic reactions to some of these items in IC patients. Positive results on skin-prick tests for cayenne (a hot pepper) seem to be common.

The foods that patients don’t realize may cause them problems—such as corn for the first patient Dr. Hubbard referred—aren’t necessarily on IC diet lists. That’s one reason the food allergy testing and treatment have been such a boon for many of Dr. Smith’s IC patients. Finding a problem food through allergy testing has an important added bonus—it leads to a more enjoyable diet.

For more about Dr. Hubbard and Dr. Smith’s research, order a back copy of the Spring 2009 ICA Update.

Blood Tests

Skin-prick or intracutaneous testing doesn’t tell the whole story about the foods that can cause reactions. Many people may have immunologic reactions that are not classic allergies, but rather sensitivities.

One example of a food sensitivity blood test is the Mediator Release Test (MRT®) developed by Signet Diagnostic Corporation. The MRT helps physicians, dietitians, and other healthcare providers design patient-specific diets based on the results of non IgE food and chemical sensitivity tests. The MRT is combined with the LEAP® (Lifestyle Eating and Performance) Elimination Diet Protocol, directed by a certified LEAP therapist. Thus far, Signet has found this approach helpful in improving outcomes for patients with irritable bowel syndrome (IBS) and migraine headaches. There are also some anecdotal reports of symptom reduction in people with IC.

Jan Patenaude, RD, CLT, Director of Medical Nutrition for Signet Diagnostic Corporation, says, “I suspect that diet is playing a much larger role than currently appreciated in IC. When you review the research regarding elevated cytokine (mediator) levels and IC, it makes perfect sense why we've seen the results we have. Remove the specific triggers, and you reduce inflammation of IC and related symptoms."

“Do we get 100% of our clients completely well? Of course not, and sometimes it’s due to patients not adhering to recommended dietary changes, but we generally see significant improvements in 80 percent of clients willing to fully follow the basic LEAP diet protocols. And generally, we see significant improvements within two weeks. Sometimes the full reduction in pain and inflammation may take six to eight weeks as the body heals and the immune system calms down; but, thankfully, improvements are often quick and dramatic.”

Posted April 08, 2011