There are about 600,000 people in the Netherlands with the respiratory disease asthma. Asthma is a chronic inflammation of the lungs that causes symptoms such as breathlessness and coughing.
According to the RIVM, people with chronic airway or lung problems have a greater risk of a serious course of Covid-19. This includes asthma patients.
Two patients on the ic
Nevertheless, lung doctors see few asthma patients end up in hospital or in the ICU after they have become infected with the corona virus.
“During the first wave we have only seen one asthma patient on the IC in our hospital, and during the second wave so far also one. That is relatively little when you consider how often asthma occurs in the Netherlands”, says Gert-Jan Braunstahl, pulmonologist at the Franciscus Gasthuis in Rotterdam. He is seen in the Netherlands as the expert in the field of asthma.
He treats dozens of patients with (severe) asthma. About 15 to 20 of his patients became infected with the corona virus in the past six months. “Two people had to be hospitalized, but in my asthma patients the corona infection has had a mild course. They had mild symptoms such as a cold, headache and a flu.”
What was striking was that the coronavirus did not seem to make asthma worse. “There has been no scientific research on this, but based on what I saw, the coronavirus does not appear to be a trigger for asthma attacks. Normally a cold or flu can make asthma worse, but we did not see that happening with the coronavirus. The asthma patients with Covid-19 that I have seen were no more oppressive from the coronavirus.
Asthma and corona: are there numbers?
In the Netherlands, no figures are kept on how many asthma patients with corona have to be admitted to hospital. “But during the first wave we did a random sample of a dozen hospitals,” says Braunstahl. “They then reported that a total of 6 to 7 asthma patients with corona were admitted to the nursing wards.”
According to figures from the RIVM, 127 people with chronic lung diseases have so far died from the corona virus. It is not reported whether these people had asthma or another lung condition such as COPD. A spokesperson for the RIVM says about these figures: “We have no picture of the distribution of underlying disorders in hospitals, but I suspect that the category ‘chronic airway or lung problems’ will mainly concern elderly people with COPD.”
Although no exact figures are known, other pulmonologists also see this picture. “We have not kept an exact record, but pulmonologists have the impression that asthma patients are admitted to hospital relatively less often because of corona”, says Leon van den Toorn, chairman of the Dutch Association of Physicians for Pulmonary Diseases and Tuberculosis (NVALT).
The same conclusions are also drawn in other countries. “Despite warnings that asthma patients may be at higher risk, they are underrepresented in mortality rates”, wrote the New York Times in May. This was also evident from a previous study published in medical journal The Lancet.
What is the cause?
Can it be explained that relatively few asthma patients are admitted to hospitals with Covid-19? “It is speculation, because so far no scientific research has been done on the course of corona in asthmatics,” says Braunstahl.
But he briefly lists three possible causes.
Strictly observe rules
“First, it may be that asthma patients adhere extremely well to corona regulations, and therefore are less exposed to the corona virus. A study that we conducted among people from different risk groups showed that asthma patients are much more afraid of to contract the coronavirus than people with diabetes or heart failure, for example, ”says Braunstahl.
“This may be because asthma patients know what it feels like to have a lung condition. They know the fear of shortness of breath.”
Puffers may have a protective effect
A second explanation may lie in the medication that asthma patients use. “The inhalers, or puffers that asthma patients use, often contain steroids. They have an anti-inflammatory effect,” says Braunstahl.
“It has not yet been scientifically established and so it is still speculation, but there are studies that show that these steroids have a protective effect, so that asthma patients are less likely to become infected with the coronavirus.”
A third cause may be that the immune system of asthma patients works differently than in people without asthma. “That is a complicated story, and not yet sufficiently researched. But in asthma patients we see relatively fewer ACE receptors in the airway mucosa. And these are precisely the receptors to which the coronavirus likes to attach,” explains Braunstahl.
“The fact that asthma patients have fewer receptors might make them less susceptible to the coronavirus. But as said, this has not been scientifically established, speculation remains for now.”
What remains is the fact that relatively few asthma patients end up on the ic or in the hospital because of corona. Can we then say that asthma patients do not actually belong to the risk group?
That is too certain, thinks Van der Toorn of the pulmonologists association NVALT. “The only well-substantiated international finding is that asthma patients in themselves do not run a clear additional risk of a bad outcome with a corona infection, but that is of course not the same as the idea that asthma patients would run less risk. no clear facts available. “
Braunstahl agrees: “Because too little research has been done on asthma and corona, it is difficult to say. What we do know now is that we have no indications that Covid-19 has a more serious course in asthma patients than with other people. But it is always wise to be careful. “