Caitlin McComish, a promising collegiate soccer player, set out for a run in her hometown of White House, Ohio, in May 2013 when she began to have trouble breathing and went into life-threatening anaphylactic shock.
As a child she'd had two or three mild attacks a year. "It's never the same, it's always like a group of symptoms," said McComish, 20.
But this one was different.
"I was right in front of my grade school," she said. "I had a really upset stomach, tingly palms and the bottoms of my feet. I was really, really itchy. It hit me like uncomfortable heat waves. Then I could feel the swelling in my throat, and my tongue got tingly and thicker."
Luckily, she said she was able to call her mother before she fell to the ground and "couldn't see straight and could barely breathe."
When the ambulance arrived, McComish's throat was nearly closed and she was barely responding. "I don't remember much," she said.
By the time she was back in fall training at the University of Toledo, she had gone into shock 17 times, always near the soccer field.
It wasn't until she was referred to the Cleveland Clinic that doctors discovered she was having an inflammatory reaction to her own sweat. She had a relatively common condition in an unusually serious form: cholinergic urticarial.
Technically, McComish doesn't have an allergy, rather she has a hives disorder when her skin is exposed to heat and sweat. The reactions are so serious, they can be life-threatening.
In a published survey of 500 high school students, researchers found an estimated 10 percent had some form of the disease, but its "true prevalence is underrated," according to Dr. David Lang, chairman of the department of allergy and clinical immunology at The Cleveland Clinic and McComish's doctor.
"It's a condition where people have itching and swelling and the major issue is heat or sweat as a provoking factor," said Lang, who has treated numerous athletes, including professionals, with the condition. "It's quite common in the general population, but in most cases, it's mild and patients either aren't aware of it or manage their symptoms well."
Strenuous exercise, even a "sit in the Jacuzzi," can trigger it, said Lang.
"The hives are very small in association with an increase in the core body temperature," he said. "Common triggers are hot baths or shower or exercise. It's one of a more common group of high-swelling syndromes."
Some people can react to cold in the same way, "when they walk outside and the winter wind blows on their face, they get swelling," he said.
Lang confirmed McComish's diagnosis with an "exercise challenge." He prescribed advancing doses of antihistamines and other medications.
She tried wearing a cooling vest while she played, she tried ice baths leading up to and following practice, but nothing helped. Finally, Lang put her on a drug used typically used for asthma, Xolair injections. She showed a "dramatic response," and was also able to continue to play soccer.
McComish also delighted in the fact that she was no longer allergic to peanuts, mangoes, celery and sesame seeds.
She said she is telling her story now so that others with similar conditions might seek help. "Somehow I got to see Dr. Lang, I think out of the grace of god."