CHICAGO (CBS) — About 50 million Americans suffer from allergies, and 3 percent of those are allergies to food.

There’s a lot of information about children with food allergies, but as CBS 2’s Mary Kay Kleist reports, those allergies can develop in adulthood, and can be very severe.

Donna Floridia’s daughter, Faith, “was living her dream at the time that she lost her life.”

Faith Floridia was just 20 years old. She was a student, a dancer and working as a waitress when she began having difficulty breathing. Her throat closed, and she went into anaphylactic shock.

“They felt it was the shrimp and crab meat she was eating,” Donna Floridia said. “I said, ‘We constantly ate shrimp how could this be?’ They said she had a sudden onset of allergies.”

Faith died a week later.

Most people don’t have such a severe reaction, but allergies can develop in adults of really any age.

“And they’re a little bit unpredictable,” said Dr. Laura Rogers, an allergy specialist in Chicago.

She says family history makes you more susceptible to developing allergies.

“If you personally have a history of other kinds of allergies, hay fever allergies or animal dander like cat allergies, you’re also at higher risk for developing other kinds of allergies such as food allergies,” Rogers said.

A severe allergy attack came out of nowhere two years ago for Gabriela Zapata-Alma.

“After dinner I had a spoonful of peanut butter, which was pretty normal for me,” she said. “And I went to bed.”

But then she woke up suddenly.

Zapata-Alma said, “I was having trouble breathing. And I was having chest pains, and so I couldn’t quite figure out what was going on with my body.”

She went to the emergency room, and eventually found Dr. Rogers. And after a series of tests, they determined she was now allergic to peanuts.

She carries an epi pen, a syringe of epinephrine to inject in case she suffers another severe reaction.

“It could have been a fatal reaction, to be honest,” Dr. Rogers said. “But most allergic reactions do not result in fatality, but with that small chance, you don’t want to take the risk.”

Common adult allergy symptoms include chronic runny nose, a post nasal drip that causes you to clear your throat a lot, nasal congestion, sinus pain, itchy watery eyes, and an overwhelming sense of fatigue.

Faith Floridia’s mother is now making it her mission to inform others about symptoms, so no one else will suffer the same tragic fate as her daughter.

“I was able to have peace and to let her go,” she said.

It’s more common for an adult woman to develop food allergy than a man.

The foods that most often trigger a reaction for adults: shellfish, peanuts, tree nuts and eggs.

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