By Greta Andrews-Taylor
Living in Perth can be kryptonite for hay fever sufferers, with the unique Australian vegetation and warm temperatures triggering plenty of stuffy noses and red, watery eyes.
But hay fever's high season of spring got a boost on Wednesday by prescribed burnings in the Perth hills - the majority of the fires in the north and east.
Pollen counts have peaked in December this year.
Asthma Foundation WA executive director Tony Carter said respiratory problems such as asthma were stimulated by warmer weather, bushfires and prescribed burnings and fires were likely to cause irritation and worsen symptoms.
"Bushfire smoke contains harmful gases and fine particles that irritate sensitive airways in people with asthma and can cause an asthma-up," he said.
A smokey haze from the fires over Perth overnight has since cleared.
Mr Carter advised those who suffered from asthma to take precautionary measures such as sealing spaces where smoke can enter and to avoid doing physical activity outside when smoke was in the air.
Smoke aside, Perth is already a hot spot for hay fever, but while the head of Princess Margaret Hospital's immunology department Richard Loh has seen a rise in allergic diseases over the years in Perth, he's not quite sure why.
Mr Loh said climate could have a role, in that droughts cause plants to produce stress proteins resulting in a lower pollen count, but that's much more allergic.
He also said change in vegetation could also be a factor and it has been about 30 years since the last proper study regarding allergies in WA.
According to Curtin University School of Pharmacy's Andrew Crowe, Australians are already at a higher risk of being affected by hay fever than Northern Europeans, as Australian plants were antigenic and more likely to stir a response in the body,
Mr Crowe said the situation for Perth sufferers was "a double-edged sword".
While rain was lowering the level of hay fever, stopping pollen from floating in the air, rain was also a major fuel for plant growth, and with more plants, more pollen would fly.
He said there could be a highly genetic link regarding the prevalence of hay fever in people, but anyone could be prone to symptoms, and he said he believed hay fever would get worse over the next month.
The Australasian Society of Clinical Immunology and Allergy said hay fever was experienced by one in five people of any age, in Australia and New Zealand.