NARRATOR:
Christina Deforges (de-forge) was only 15 years old when she died from a most unusual cause - a kiss.
The Canadian teenager was allergic to peanuts, and her boyfriend had eaten peanut butter hours earlier. Doctors say traces of peanut butter remained in the boy's mouth, setting off Deforges' allergic reaction.

MICHAEL SAINT GELE, BOYFRIEND: (needs translating)
"I looked down and realized she was having problems breathing. She was not doing well at all."

NARRATOR:
Michael Saint Gele, Deforge's boyfriend, was unaware of her allergy, which caused her to go into shock. Though she immediately received a shot of adrenaline, she died four days later in a Quebec hospital.

Symptoms of peanut allergies can include hives, a rapid drop in blood pressure, swelling of the face and throat, and shortness of breath.

Twenty-year-old Michelle Risinger suffers from peanut allergies. She once kissed a boy who had eaten a cookie with trace amounts of peanut.

MICHELLE RISINGER:
"My throat closed. It's a tight tingling sensation. Then my body swells with hives."

NARRATOR
About 1.5 million Americans are severely allergic to even the smallest trace of peanuts, and peanut allergies account for 50 to 100 deaths in the U.S. each year.

Dr. Hugh Sampson, a professor of allergy and immunology at Mt. Sinai Medical Center in New York, says the death rate in America from peanut allergies is higher than other countries because Americans eat more dry roasted peanuts, compared to the boiled or fried peanuts eaten in Asia.

DR HUGH SAMPSON, MT. SINAI MEDICAL CENTER
"Roasting... brings about a change in the structure of the protein that makes it much more likely to cause an allergic reaction."

NARRATOR:
The incidence of peanut allergies in America has doubled in recent decades. They now affect about one percent of the population under 18. The reason is unclear, but some doctors say increasingly clean homes prevent exposure to germs and other substances, so children's' immune systems do not develop fully.

Paige Kollock - VOA News.