EILO stands for exercise induced laryngeal obstruction and it is a newly understood reason for DOE (dyspnea on exertion) especially in children and adolescents.
Dyspnea (breathlessness) on exertion can occur for very diverse reasons including anemia, cardiovascular problems, neuro muscular problems and respiratory issues. The most common respiratory cause for DOE is exercise induced bronchospasm (EIB) due to underlying asthma. But asthma is an exhalation disease; that is, the main issue is getting air back out of the lungs. EILO is an inhalation disease. The larynx narrows with breathing in and causes stridor. The narrowing doesn’t occur when the individual is at rest. To complicate matters EILO can occur in asthmatics, so it’s important to understand the distinction.
The University of Cincinnati Children’s Hospital has contributed significant understanding to EILO. They feel it’s part of the spectrum of other laryngeal problems including irritable larynx syndrome and paradoxical laryngeal motion (also known as vocal cord dysfunction).
Interestingly, using an asthma rescue inhaler prior to exercise does not prevent EILO (but it works like a charm for EIB). What helps these patients most is retraining their laryngeal muscles via exercises prescribed by a speech pathologist.