Julie Bowen of "Modern Family." Paul A. Hebert/Getty Images.

What are the odds a child will be exposed to two powerful allergens at the same time? It happened to " Modern Family" actress Julie Bowen's son. He was stung by a bee - at the same time he was eating a peanut butter sandwich.

The toddler immediately went into anaphylactic shock. His entire face swelled up, including his eyes and lips, and his breathing became labored.

"We took him to the ER, where he was treated with epinephrine, and ever since then we've been vigilant about keeping him safe," the Emmy-winning Bowen told the Los Angeles Times.

Bowen told the paper she's speaking about the experience publicly because one in 13 children have food allergies and she wants to educate parents about the dangers.

According to Dr. Brian Schroer, a pediatric allergist with the Cleveland Clinic in Ohio, childhood allergies can indeed be serious business. Parents need to know what to watch out for.

"When introducing a new food to a young child, especially a common allergen, watch closely for signs of distress," he said.

The most common food allergy symptoms are itchiness in the mouth, a rash on the face, the body or both, coughing, wheezing and vomiting.

If a child's allergy is severe, as in the case of Bowen's son, there will also be facial swelling, difficulty breathing and low blood pressure. Schroer said the Bowens did the right thing by rushing their son to the emergency room.

"Parents can also give their kids some Benadryl to help symptoms but should still seek urgent care," he said. "For a child really in distress, call 911."

Children may not have a reaction the first time they're exposed to an allergen. Initial reactions can range from mild to severe, with the most profound reactions generally triggered by peanuts, tree nuts and shellfish. Insect strings also tend to produce strong reactions. However, even a mild symptom like itchiness or a light skin rash can portend more serious reactions in the future.

At the first sign of any allergy symptoms, Schroer recommended checking in with a pediatrician or allergist.

"They can take a complete medical history and conduct simple skin challenge tests to determine the cause," he said."If there is an allergy, parents should work with their doctor to create a food allergy action plan."

Once a plan is in place, make sure everyone who cares for your child, including teachers, babysitters and after-school providers, are familiar with it. Schroer said sometimes that means giving a stern lecture to well-meaning grandparents who may not quite believe the child has an issue until they see it for themselves. And any child who is at risk for anaphylaxis should carry an epi-pen and other medications at all times, including school, play dates and vacation.

Bowen hopes there won't be any more "P Bee and J" situations for her son. But if there are, she said she's prepared. As she told the L.A. Times, "It's pretty straightforward. I don't need to know everything that happens during an anaphylactic reaction; it's enough for me to know as a parent that it can kill you."