Larygnospasm (the most severe form of vocal cord dysfunction) is commonly misdiagnosed as asthma and patients may go for years labelled as asthmatic even though they may not have it at all.
However, though laryngospasm is often the victim of misdiagnosis, there is a condition known as non-organic stridor which is often misdiagnosed as laryngospasm (culprit as well as victim of misdiagnosis).
Here is a video example (watch the movie clip all the way to the end) of a patient with non-organic stridor who was initially misdiagnosed with asthma, than misdiagnosed as having vocal cord dysfunction/laryngospasm before being finally correctly diagnosed with having non-organic stridor.
As you can see, the vocal cords remain apart which immediately rules out the diagnosis of laryngospasm.
What is also apparent is the wheeze or stridor noise is due to vocal cord vibration while they are apart.
The fast moving inhalation/exhalation literally rattles the vocal cord membranes just like a strong wind flaps around an American flag resulting in "noise". No need for the vocal cords to come together to create the noise. The fast moving air does it all by itself.
The existence of non-organic stridor is one of the main reasons why laryngoscopy during a "breathing attack" suspected to be due laryngospasm is so important.
It's also why I have my patients run around my office until they become symptomatic before I perform this exam. Why do an exam when breathing is completely normal???
What is the treatment? Just reassurance... Given it is the fast-moving air that is causing the noise, one simply has to slow the breathing down. No inhalers, no epinephrine, no medications are needed.
For whatever reason, by far the most common patient who suffers from non-organic stridor is a female high school athlete.