Season for sneezin’: Why hay fever sufferers are in for another ‘bad’ spring

Ah-choo! Spring has sprung, and with it, the annual onslaught of sinus-invading pollens. Experts tell Jamie Morton why this season might be particularly troublesome for hay fever sufferers.

Why is this a notorious time of year for hay fever?

Your eyes are itchy and watery, your nose is running, your throat feels scratchy and you’ve lost your sense of smell.

For hundreds of thousands of Kiwis who suffer seasonal allergic rhinitis, spring hay fever isn’t something to sneeze at.

It’s typically triggered by dust mites, pets and mould and, especially at this time of year, windborne pollens from flowering trees, grass and weeds.

Annoyingly for sufferers, those pollens don’t hit us all at once: those from trees are floating about now, while grass and weed pollens take flight in late spring and summer.

Yellow dust gathering on windscreens is a classic sign of pine pollen increasing around early spring. Photo / Duncan Brown.

Allergy New Zealand chief executive Mark Dixon explained that, when those tiny pollens were inhaled and detected by our immune systems, an allergic reaction sometimes followed.

That involved the bloodstream being filled with chemicals such as histamine and leukotrienes, known to inflame the lining of our nasal passages and sinuses.

How bad is this season likely to be?

Kiwis might have already noticed their patios and windscreens caked in yellow dust from pine pollen, but there’s much more in the mix.

“Tree pollen season is just getting under way now and it also involves oak, hazel, maple, and poplar,” MetService’s pollen forecaster Dr David Fountain said.

“People might have noticed seeds and other fluffy stuff being carried in the wind, but these aren’t as allergenic as we think: it’s those invisible pollens that are the biggest problem.”

Last spring, the arrival of El Nino and its signature westerly winds were blamed for driving a bumper pollen season that caused havoc for hay fever.

While that climate pattern has since faded, forecasters say blustery westerlies will be frequent in the weeks ahead.

Now is the time of year when pollen from pines and other trees take to the air.

“Those westerly conditions move the pollen around a lot more, so for people with hay fever, yes, it’s going to be a bad season,” Fountain said.

The good news, Niwa meteorologist Ben Noll added, was a developing La Nina could lead to weaker winds towards the end of the season - just as those grass pollens began spreading.

“The flipside of that it could come with more warm or hot temperatures, which makes for good growing conditions.”

Is hay fever season getting worse?

Hay fever is also known to be an extremely common trigger for children and adults with asthma - with an estimated 80% of asthmatics suffering from it.

While there’s now plenty of health data to show New Zealand has comparably high rates of childhood asthma – and that asthma attacks are generally increasing – less is known about what’s driving the trend.

One likely factor is an increase in pollen in the air.

When scientists recently set up a pollen trap atop the Auckland War Memorial Museum, they found days of high pollen volumes being recorded had jumped 75% compared to the last time measurements were done, 35 years ago.

A team of scientists recently set up a spaceship-like pollen trap atop the Auckland War Memorial Museum to analyse fine particles flowing through our air. (From left) University of Auckland researchers Dr Stuti Misra, Dr Amy Chan, and Natasha Ngadi. Photo / University of Auckland

Climate change – driving warmer temperatures that prompt plants to produce more pollen over longer growing seasons – is one potential background factor.

A changing climate was also linked to more “thunderstorm asthma”, where big weather events coincided with high-pollen periods.

There are other open questions about changes in our environment - namely green spaces and forestry – and whether there might be emerging pollen allergens that weren’t picked up in the last assessment in 1988.

What do people need to know?

“For people at risk of allergic asthma, now is the time to make sure they’ve got their asthma management plans on hand,” Asthma and Respiratory Foundation chief executive Letitia Harding said.

“Keeping a diary of when it’s worse is always a good idea, as is letting family and friends know.”

With the weather warming, more Kiwis are getting outdoors - and asthma sufferers can run into trouble when they forget to take their inhalers and medication with them.

“If you’re someone who gets affected by pollen during hay fever season, it’s also a good idea to make sure you shower every night, because even when you’re out and about, pollen can settle on your clothes.”

University of Auckland asthma expert Dr Amy Chan suggested tips such as covering up while outside, use air conditioning while driving, keeping homes clean, staying hydrated, taking antihistamines before bed and trying anti-allergy medication if needed.

Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.

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