NORTH WALES, Pa. (WPVI) --When you think of food allergies, you think of sharp reactions to things like peanuts or eggs. But some food allergies may be more subtle, and go undetected.
Now, one local doctor is helping patients connect the dots.
For nearly 10 years, Diane Pennell was told her abdominal problems were due to Irritable Bowel Syndrome - a common digestive disorder.
She avoided certain fruits and vegetables like her doctor said, but it wasn't working.
While visiting her dermatologist, Dr. Michael Stierstorfer, she noticed a sign offering patch testing - the kind used for skin irritations like eczema.
Pennell got tested and had reactions to cinnamon, Benzoyl peroxide - which is used to bleach flour - and several preservatives.
"I didn't actually know I was eating cinnamon, but it did learn that it's found in ketchup, spaghetti sauce and Russian dressing," she said.
After a lot of label reading, Pennell adjusted her diet and is feeling the changes.
"I feel great! It's a hundred and eighty turnaround," she said.
Dr. Stierstorfer's own IBS launched this approach.
Frustrated he couldn't find a food causing his pain and discomfort, he started thinking about ingredients, specifically garlic, used in food everywhere.
"I stopped garlic, and within a day or two, I was fine," he recalled.
A patch test confirmed that - the garlic caused a red spot.
And a full series of skin tests zeroed in on more culprits.
"The same kind of inflammation I was getting from the patch test was probably occurring in the lining of the intestinal tract," said Dr. Stierstorfer.
He calls the condition Allergic Contact Enteritis, or ACE.
Published studies with patient volunteers are now getting national attention.
Meanwhile, Dr. Stierstorfer has expanded testing to 122 allergy triggers.
"We're helping about 60% of the people we're testing," he said.
The most common triggers are cinnamon, garlic, preservatives, some red food dyes, Benzoyl Peroxide and nickel.
Surprisingly, whole grains, oatmeal, nuts and soy all have trace amounts of nickel.