If you flew abroad this summer, you probably passed through an airport’s duty-free perfume section. Perhaps you paused to spritz yourself with an expensive scent you had no intention of buying, before making the obligatory trip to WH Smith for overpriced crisps and bottles of water.

For most people, the wafting odours of perfume counters are not a problem. But, for some, the trip through duty free is a choking, cloying experience.

Research published this year found that one in three adults claim to have experienced health problems caused by fragranced products, whether perfumes, cosmetics, laundry detergents or soap. The study found that fragrance sensitivity caused migraines, watery eyes and respiratory issues. More than 4,300 people from the UK, the US, Australia and Sweden responded, including 1,100 from the UK. Speaking to the New Scientist, the lead researcher, Dr Anne Steinemann – a professor at the University of Melbourne – characterised fragrance sensitivity as a healthcare epidemic of which we don’t yet know the scale. She suggested that fragrances should carry clear labels about their ingredients.

Increasingly, airports are recognising the problem, with Helsinki, Vancouver and Copenhagen among those offering perfume-free routes for passengers with fragrance sensitivities. Legislators are also responding to the need for fragrance-free public spaces: most hospitals and schools in Halifax, Nova Scotia, ban employees from wearing perfume, while in Oakland, California, city officials ask residents not to wear scents to public meetings. And you can forget about dousing yourself in Old Spice before slinking into your weekly encounter with the Almighty: a church in suburban Seattle made headlines in 2013 after introducing fragrance-free zones.

One day, all public spaces may be scent-free. It is bad news for the perfume manufacturers, but good for people such as Lesley Heidinger, a 46-year-old call-centre worker from Edmonton in Canada. Heidinger has multiple chemical sensitivity (MCS), a little-known condition characterised by heightened sensitivity to a wide range of chemicals, many of which are commonly found in soap, detergent, sanitiser gels and perfumes. She can tolerate natural scents, including most essential oils, but synthetic fragrances are bothersome. If Heidinger inhales a colleague’s scent, her sinuses will become irritated, she will wheeze and cough and it will bring on a migraine that can last for days. Other reported symptoms of MCS include muscle pain, exhaustion and disorientation.

“It’s a constant battle,” Heidinger says. She has been off work for much of the year, as her symptoms have been particularly bad. Although her employers have implemented a scent-reduced zone around her desk – meaning that colleagues in her immediate vicinity have been asked not to wear fragrances – this doesn’t apply to communal spaces. “I don’t know if people realise the real impact of it,” she sighs. “It makes me incredibly ill. Having a migraine for a week is really unpleasant.”

Heidinger is also sensitive to smoke and the fragrance from washing powder and fabric conditioners. Things got so bad that she had to sell her flat, because it had a shared laundry room, and move somewhere with its own washer-dryer, so she wouldn’t be exposed to the smell of other people’s laundry. On a recent flight to Italy, Heidinger had to switch seats because the woman next to her was wearing perfume. “I could smell it as soon as she sat down. I just said: ‘I can’t sit next to you.’”

Heidinger’s MCS is medically recognised: she has been diagnosed by her doctor and receives disability benefits when she is unable to work. But not everyone is met with compassion and validation by medical professionals. Online forums for people with MCS are full of stories of not being taken seriously by doctors, while there is debate within medicine about whether MCS is physiological or psychological. A US study in 2011 found that only 30% of doctors surveyed had received formal training about MCS. The NHS website does not publish treatment guidelines for MCS.

“These people are orphans of conventional medicine,” says Dr Apelles Econs, an allergy specialist at the Burghwood Clinic in Surrey. As people with MCS are intolerant of chemicals, rather than allergic to them, allergy tests often come back negative. “They may be told they’re imagining it, and referred to psychiatric colleagues to see if they can manage the condition,” Econs says. “But, in reality, the root of the problem has not been addressed properly.”

“It’s an under-recognised condition,” agrees Prof Howard Hu, a leading environmental health expert at the University of Washington School of Public Health. (MCS is sometimes referred to as environmental illness, as sufferers are triggered by external chemicals in their living and working environments.) But Hu believes the medical community’s perspective on MCS is changing. “There’s some decent research coming out ... In my opinion, the evidence is good that there’s something neurological going on that’s triggered by an odour and leads to a cascade of events in the brain that manifest as these symptoms. Is it physiological or psychological? It’s somewhere in between – the tools we have to investigate these disorders are still pretty primitive.”

Until more is known about MCS, offering fragrance-free public spaces would be a welcome move. “It would be miraculous, because of how ill being exposed to something makes me,” Heidinger says. “It’s really demoralising not to be able to go to work and enjoy life to its fullest because of this. It’s not a fun way to live.”