Aaah, spring! Honestly, it’s almost here, with buds, birdsong, daffodils, lambs and calves (in the paddocks if you live in the country, or at the petting zoo if you’re a city dweller), and that first sneaky feeling that warmer days might be on the way. Along with this are also the snuffles and sneezes, for us Tasman neighbours are among the highest suffering nations of hay fever in the world.
Some three million Australian adults and as many as 1.5 million New Zealanders – one-third of the Kiwi population – need to reach for the tissues and antihistamines in what’s now known as “the allergy season”. As if we didn’t have enough reason to worry about the effects of climate change, here’s one more. Studies show that global warming has resulted in plants producing more pollen, so the allergy season is lengthening and the effects for most sufferers are worsening.
Dr Zac Turner has said that London plane trees – which make up almost 70 per cent of Sydney and Melbourne’s tree population – may be the cause of increased hay fever cases in Australia’s most populous cities this year.
‘The tree’s falling leaves release soot hairs known as trichomes (which are fine, spiky hairs that cover the young leaves of plane trees) during the peak of spring,’ he said.
The fine particles emitted from the plane trees are known to cause throat irritation and laryngospasm, and spasm of the vocal cords.
Welcome to the lazy, hazy, crazy days of watery eyes, runny nose and itchy throat.
Technically, says allergy expert Mark Dixon, hay fever is an allergy to grass pollen in spring. Allergic rhinitis is an allergy to environmental factors such as pollens (including grass), house dust mites, cats and other pets. When people who are susceptible to hay fever are exposed to particular pollens, their body mistakenly thinks it’s a threat and triggers an allergic reaction. Inflammatory cells quickly release mediators such as histamine, then those all-too-familiar symptoms start to kick in.
The bigger issue
It’s not just an irritation. Dixon says many people underestimate how much their health and wellbeing is affected by a blocked or runny nose, red and itchy eyes and sneezing.
“They can cause disturbed sleep, leading to tiredness and lack of ability to concentrate. If this is regular, every night for weeks, then it is very difficult to function at top level. However, most people tend to rely on over-the-counter medications and don’t get good advice on how to minimise their symptoms. Allergies are lifelong and the triggers are usually very difficult to avoid.
“So if they are significantly affected, they should see a GP or possibly an allergy specialist to confirm what they are allergic to, ensure they have the right medications and know how to use nasal sprays properly,” Dixon explains. “They may also like to discuss desensitisation, which is the only treatment that can make a significant difference long-term.” In desensitisation, now generally known as allergy vaccination, small amounts of a particular allergen are injected, so the patient’s body builds up immunity to the triggers for an allergy. When the patient is exposed to those allergens in the future, that person will have a reduced or minor allergic response and fewer symptoms. Recognising that hay fever and allergic conditions are more than a minor irritation, Dixon’s organisation has appealed to the government to investigate the hidden socio-economic impact that the condition has on patients and their families. “There can be fatigue, irritability, anxiety, depression, frustration and lower energy levels. Symptoms of allergic rhinitis including pollen allergy are associated with economic costs such as loss of work and school productivity,” Dixon points out.
As far back as 2007, a study on the economic impact of allergic disease in Australia for the Australasian Society of Clinical Immunology and Allergy (ASCIA) estimated they cost the country $7.8 billion each year, including $1.2 billion in direct medical expenses. The drastic rise in recorded rates in the past decade suggests the report’s title was prophetic: it was called Not to be Sneezed At. In 2014, Allergy New Zealand estimated the socio-economic cost of allergies in that country at $5 billion per year.
Deep roots: Why do both countries have such high rates of hay fever?
The answer seems to lie in the soil – or not too far above it – and has its roots in the historical bedrock of both economies. Blame the grass that settlers introduced from Europe to our southern hemisphere environments to create dairy, beef and sheep farms. Grass pollens are the major outdoor trigger for hay fever in Australia and New Zealand.
The timing and severity of the grass pollen season varies considerably between years and places, according to a recent analysis of 17 sites across both countries.
Problematic plants in Australia and New Zealand
Melbourne usually has a short but intense season, peaking from October to November. In Hobart, the season peaks slightly later and the pollen load is low. The season for Brisbane and Darwin covers most of the year, with Brisbane seeing peaks in January to March. For Darwin it’s May to June, the dry season. Adelaide, Sydney and Canberra have their season in spring but have secondary peaks in summer.
In New Zealand, perennial ryegrass, the most common grass on farms, causes the biggest problem.
The pollen season varies, starting about a month earlier at the top of the North Island than the bottom of the South Island, according to a study by Dr Vincent St Aubyn Crump of the Auckland Allergy Clinic. Auckland’s main pollen season is between October and February, but the seasons depend on factors such as El Niño weather patterns, it can move as much as a month either way. Dr Crump notes pollen concentrations are lower in coastal areas, but everywhere in New Zealand is surrounded by grazing lands, so inland cities such as Hamilton and Palmerston North can have relatively severe seasons. Short of uprooting every blade of introduced grass on every farm, lawn, cricket oval or football pitch on both sides of the Tasman, it seems millions will have to sneeze and bear their affliction for the foreseeable future – even that might not work.
As Chile’s Nobel Prize-winning poet Pablo Neruda wrote, “You can cut all the flowers but you cannot keep spring from coming.”