In two years, professional triathlete Danielle Mack saw 18 different physicians: family doctors, gastroenterologists, neurologists, allergists, pulmonologists and specialists of other sorts. She had many tests, but she got no explanations for what she called her “invisible illness.”
Mack’s symptoms included numbness in her legs, lightheadedness, dizziness, shortness of breath, chest pain, nausea and full-body cramps. The signs suggested exercise-induced asthma. Her physicians treated her with an inhaler, which not only did not work but also made her feel worse. Finally, Mack, who lives in Boulder, Colo., tried a stress test at National Jewish Health Hospital in Denver.
Under the supervision of pediatric pulmonologist Tod Olin, Mack rode a stationary bike while a tiny camera, inserted through her nose, filmed her vocal cords. As she increased her pace, the cords narrowed, blocking air. The result: a repeat of the symptoms she had been experiencing while training and racing. Olin diagnosed her in September with exercise-induced laryngeal obstruction, or EILO.
Exercise-induced respiratory symptoms are fairly common in adolescents and young adults (Mack is 30 years old), and the most likely explanation is asthma. A condition that has been recognized since the early 1980s, EILO is often missed by physicians, Olin said.
“Without intending to, patients often mislead doctors by unconsciously using the word ‘wheezing,’ which causes confusion,” Olin said. “If patients were to act out symptoms, the physicians could make a more accurate diagnosis, but that’s generally not part of the routine screening.”
This confusion leads physicians to prescribe asthma medicine, as in Mack’s case. “The next step is often to throw more medicine at the problem,” Olin explained, “which doesn’t fix anything.”
The prevalence of EILO is surprisingly high, Olin said, at around 5 percent of adolescents and young adults.
“Compare that to Type 1 diabetes, for instance, which is around 1 percent,” he said, “or asthma, which stands at 8 to 12 percent.”
Perhaps even more problematic is the lack of knowledge about treatment.
“The clinical reality is that even if you have the right diagnosis, the breathing exercises that have served as the standard really don’t work for most patients,” Olin said. “By the time patients get to me, they’ve inevitably tried multiple approaches and are discouraged and frustrated.”