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Allergies Health Center

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Could It Be an Allergy?

Telling the difference between an allergic reaction and something else can be tricky.
WebMD Feature
Reviewed by Laura J. Martin, MD

Wondering if your nagging cold is actually an allergy? Or what about your new skin cream that made your hands break out? Distinguishing an allergy from a non-allergic condition is not always a clear-cut task. But knowing the difference can sometimes help you solve what's ailing you, which in turn could mean faster relief.

Mary Fields knows just how difficult pinpointing an allergy can be. The 64-year-old Bronx resident tells WebMD she was convinced her frequent hives were caused by something in her diet.

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Food Allergies: Tips for Eating Out

Having a food allergy used to mean dining out was limited to carrying your plate from the kitchen to the porch or, at best, eating at the home of a close friend or relative who could guarantee your food offenders were nowhere in sight. Today, however, eating out is a lot easier -- and safer -- for the 2 million Americans who suffer with a mild, moderate, or even a severe food allergy. One reason: Restaurants are more aware and more prepared. "The awareness of food allergies has definitely increased...

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"At first I thought I was allergic to chocolate, so I stopped eating that, but it still came back and even started to spread from my arms and legs to my back and thighs," says the retired nurse's assistant.

Fields' dermatologist referred her to allergist David Resnick, MD, FAAAAI, who ran a battery of allergy tests on her. "All the tests came back negative. This isn't an allergy. Her hives got increasingly worse with stress, which might be a part of it. But her symptoms are idiopathic, meaning their origin is unknown," says Resnick, who directs the allergy division of New York-Presbyterian Hospital/Columbia University Medical Center.

"I was a little surprised it wasn't food," says Fields, who says the hives started when her husband was diagnosed with a heart condition and needed to have a pacemaker implanted. "I was going through a lot of stuff but I didn't realize I was worrying. So I'm trying to keep myself calm now, to start releasing some of the stress, and I guess I'll see if that stops the rash."

Mistaking Allergies: Easy to Do

Fields isn't alone in thinking an allergy was at the source of her outbreaks. Many people see just about any bad reaction to be an allergy, which isn't surprising, since more than half of all Americans test positive for at least one allergen, according to the American Academy of Allergy Asthma and Immunology.

Technically speaking, a true allergic reaction happens when the body mounts an unusual immune response to something that's normally harmless. Most allergy tests check for higher levels of antibodies known as Immunoglobulin E (IgE) in the blood, which are launched by the immune system to fight the invading substance.

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