Air pollution may be a cause of eczema, new research suggests. The study shows that people who live in cities with high levels of pollution are at greater risk of developing the condition.
They are also more likely to experience eczema flare-ups when air quality is considered "average" - as is often the case in London and New York, according to the same study.
This discovery comes just days after experts found that air pollution inhaled by women during pregnancy may be linked to a greater risk of autism in their offspring.
In this new research, American researchers followed over 286,000 adults in more than 780 areas, asking them about their overall health.
Average levels of particulate matter with a diameter of less than 2.5 micrometers (PM2.5) near their homes were also analyzed.
These microscopic particles are the smallest in the air and can penetrate deep into body tissues, being linked to problems like heart disease and dementia.
Factors that could influence the results, such as food allergies and smoking status, were taken into account.
Researchers from Yale University in Connecticut found that for every 10 micrograms per cubic meter increase in PM2.5, cases of eczema more than doubled.
Jeffrey Cohen, lead author of the study and assistant professor of dermatology at Yale University, said: “In the most polluted areas of the country, there were more cases of eczema.”
In a publication in the journal PLOS ONE, the researchers added: "Showing that individuals in the United States exposed to airborne particles are more likely to have eczema deepens our understanding of the important health impacts of air pollution."
However, the scientists acknowledged that the study had some limitations, including using PM2.5 data only for 2015.
The World Health Organization (WHO) has long called for countries to take tougher measures to combat pollution, which is thought to kill 7 million people each year worldwide.
What is eczema?
Eczema is a group of inflammatory skin conditions that cause itching, dryness, redness, scaling, and infection, and affects up to 25% of the population.
The condition can worsen to the point where it becomes devastating, causing skin inflammation throughout the body.
At least one in ten children will have eczema at some point, but they usually outgrow it as their immune system develops.
It is thought that eczema occurs in people with a common genetic mutation that causes severe dryness of the skin.
Outbreaks of symptoms can also be related to allergies or triggered by certain soaps or foods.
Dermatologists usually prescribe creams and washes to treat dry skin, as well as steroid creams to reduce swelling and redness.
If these do not work, immunosuppressive drugs, such as cyclosporine or methotrexate, are used.
The connection with autism
Also, this week researchers suggested that air pollution may be linked to a greater risk of developing autism.
A review of recent scientific literature showed that infants with a high genetic risk for the developmental disorder, exposed to four common air pollutants, were more likely to develop the condition.
It is thought that these microscopic pollutants, when inhaled during early childhood or development in the womb, can enter the bloodstream.
There, they can overcome the brain's protective layers, causing inflammation, changing the way nerves function and increasing the risk of disorders.
The rate of autism has exploded globally.
Analysis shows that diagnoses of the disorder have increased by almost 800% in Britain over the past few decades, while rates have almost tripled in the US. /Express newspaper/
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