But new research suggests that deaths from the respiratory disorder among children and younger adults in England was more common in affluent areas.
One possible explanation is that cleaner homes increase the risk of childhood allergies.
Some scientists think a lack of early childhood exposure to germs increases the chance of allergic diseases and that over-sanitisation might suppress the natural development of the immune system.
There were 14,830 recorded asthma deaths between 2002 and 2015 in England, including more than 1,400 among children and adults aged between five and 44.
There were more than 500,000 emergency asthma admissions from 2001 to 2011 among patients aged five and over.
After analysing the data, experts from St George’s, University of London, and the University of Edinburgh found an “unusual and unexpected pattern” – that asthma mortality among those aged between five to 44 was more common in more affluent areas.
In results published in the journal Thorax, researchers found that in most age groups the rate of asthma deaths was generally higher as deprivation increased, apart from those aged five to 44, where they noted a “modest but significant decrease in deaths from asthma with increasing levels of relative deprivation”.
In that age group mortality was 19 per cent lower among the most deprived 20 per cent, compared to the wealthiest 20 per cent.
But almost any food – including fruits and vegetables – can cause a reaction.
Despite improvements in care and falling numbers of asthma deaths the UK still has among the highest mortality rates in the world among the young.
It also has significant differences in “asthma outcomes” across different regions and socio-economic backgrounds, added the experts.
Sufferers in the West Midlands are more likely to die than patients in other parts of the country.
Experts speculated that affluent areas may have a higher prevalence of “a less predictable, more brittle” form of asthma which can progress more rapidly and lead to death.
There may also be higher prevalence of allergies in wealthier families.
Allergies occur when the body’s immune system mistakes proteins in food as threatening and reacts as if there was an infection.
Common food allergies in children include milk, eggs, peanuts, fish and shellfish.
Researchers found mortality rates in the region were about a third higher than the England average.
Emergency hospital admissions for asthma – which affects more than five million people across
Britain – were commonest in the North-west.
Dr Samantha Walker, of Asthma UK, said: “It is concerning and unexpected that younger people in England who are wealthy have a higher risk of dying from the condition than those who are poor.
“More research needs to be done to fully understand the relationship between someone’s socioeconomic status and how their asthma might affect them.”
