Asthma Subgroups: Nocturnal Asthma
Maimonides lived from 1134-1204 A.D. He may have been the first physician to describe nocturnal asthma.1 Modern physicians recognize it as a viable subgroup of asthma. Yet it still remains poorly understood. So, what is nocturnal asthma? Here’s what to know.
What does history show?
Thomas Willis was another physician to recognize nocturnal asthma. He lived from 1621-1675. He is often credited with fine tuning the definition of asthma. Prior to his time, asthma was a symptom. If you complained of shortness of breath, you were diagnosed with asthma.2
Asthma as a disease
Willis was the first to define asthma as a disease. He defined it as obstruction of the bronchial tubes. As with many physicians of old, he believed it was caused by thick "humors." Humor is an old term for phlegm. So, he believed asthma was caused by phlegm. This makes sense, as phlegm can obstruct airways.2
Nocturnal components of asthma
However, he went a step further. He also described a nocturnal component of asthma. He believed heat from the bed caused it. His treatment was sleeping in a chair. This was a step up from the treatment recommended by Maimonides, which was celibacy.2
Both these physicians were on the right track in describing nocturnal asthma. Modern physicians are well aware of it. Studies show 75% of asthmatics experience it on a weekly basis, while 40% experience it every night.3
We're still learning today
Still, like Maimonides and Willis, modern researchers are left to speculation as to the cause. They also remain obtuse as to the best treatment. The big difference is modern researchers have evidence from science with which to draw their speculations from.
What do modern researchers think?
So, evidence shows most asthmatics have some degree of nocturnal asthma. The most common symptoms are shortness of breath and/or coughing. These symptoms cause asthmatics to wake up during the night.3
Now, researchers do know a few more things about it than Maimonides and Willis. They know that during the night their airways become inflamed. This makes airways hyperresponsive.3 This means they are extra sensitive to asthma triggers. Nighttime triggers may include allergens, such as dust mites and animal dander. It may include things like gastrointestinal reflux or humidity.
They know that they suffer from a drop in FEV1 of 15% or more while sleeping. FEV1 is a good indicator of lung function. So, nocturnal asthma causes a drop in lung function. And this causes asthma symptoms. And this is what keeps them awake at night. To learn more on this aspect of nocturnal asthma, read our post, “Nighttime Asthma.”3
What causes this to happen remains a mystery. But there are some theories. I will cover these theories in an upcoming post. So, stay tuned for that. In the meantime, Theresa explained some theories in her previous post on nocturnal asthma.
What is the treatment for nocturnal asthma?
There is no specific treatment for nocturnal asthma. Doctors usually treat it the same way they treat persistent asthma. The goal is to prevent symptoms by obtaining good asthma control. This is usually accomplished with front-line asthma medicines. These include beta adrenergics and corticosteroids. The idea is that better asthma control can prevent nocturnal asthma.3
If nocturnal symptoms persist, doses can be adjusted. If they still continue to persist, second line asthma medicine may be considered. These include medicines like Singulair, theophylline, and biologics. It may also include COPD medicine. So, there are various options for treating it.
What to make of this?
Maimonides recommended celibacy. This treatment was based on negligible evidence. Today, the best strategy is to treat it like persistent asthma. This helps many but not all who are plagued by nocturnal asthma. So, researchers continue to research this asthma phenotype. The goal is that, as more is learned about it, more specific treatment options will hopefully be discovered.
So, what causes nocturnal asthma? What exactly happens inside lungs at night to contribute to nighttime asthma? The answers to these questions will be the subject of an upcoming post. So, stay tuned!
In the meantime, if you have any questions about nocturnal asthma, please reach out in our forums.
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