Is Hay Fever a Genetic Condition?

Pollen time is misery time for about 15% of the Australian population or about 3.1 million people afflicted with hay fever or allergic rhinitis.  Most of these sufferers (about 2 in 10 people) live in Canberra and Western Australia, areas with the highest grass pollen counts.

For people unfortunate to possess an immune system overly sensitised to pollen, pet dander, dust mites, mould, and cat saliva, everyday can an ordeal of irritated sinuses; perennial runny noses; sneezing; and red, watery eyes.  Especially during pollen season, everyday is sick day which affects people’s social lives and productivity.  The hardest hit age group is the middle or working years, between the ages of 25-44 years old, more than children or seniors.

What Hay Fever Is

Hay fever, also known as allergic rhinitis, is an allergic condition in which a person’s immune system reacts to normally innocuous substances such as pollen and fungal spores with an abnormally protective response.  The immune system perceives these substances (which it now identifies as allergen triggers) as harmful and thus releases histamine into the bloodstream, causing sinus, eye, and airway inflammation.

Hay fever comes in two types:  seasonal and perennial.  The seasonal kind occurs only during the time of year when plants pollinate.  The perennial type, sadly, plagues the sufferer all year round.

Many Australians are particularly allergic to pollen, so much so that as few as 50 microscopic grains of these per cubic yard of air are enough to trigger a violent allergic reaction.  Grass pollen, in particular, has proven to be a major culprit of allergic rhinitis and asthma.  Hay fever or allergic rhinitis that is triggered by pollen is also called pollinosis.

Where you live in Australia may be a huge factor of when your hay fever strikes.  Knowing when pollen season arrives at your region may help you prepare adequately to pare down the symptoms.  The better prepared you are at worst of pollen time, the better you can cope with work, social, and family demands in those debilitating months.  Yes, hay fever can be debilitating especially if your immune system’s reactions get particularly severe.

Not everyone of course suffers allergic rhinitis; so, what makes one more susceptible to hay fever than others?  Is hay fever even hereditary?

Risk Factors for Developing Hay Fever

Although allergies can be developed by anyone, one is more at a high risk of developing them if one’s family has a history of allergies.  As an allergy, hay fever tends to be hereditary.  One is more likely to be born with the genes for it especially if one’s mother has allergy problems.

Aside from the genetic factor, other high risk factors for hay fever include:

• Having other allergies -- If you are prone to other allergies, you are more likely to be susceptible to hay fever as well.


• Having asthma -- Asthma and hay fever are closely tied.  People afflicted with asthma may acquire hay fever as well.


• Being the firstborn -- Interestingly, being born first of your siblings can be a high risk factor for allergic rhinitis and other allergies.  This phenomenon may be attributed to the hygiene hypothesis which attributes first time parents to over-sterilise the environment, consequently leaving the eldest child with less opportunity to strengthen his immune system from germs. With more experience, parents get to relax with clean-ups so that subsequent children get to have more germ contact and a bolstered immunity.
  
  Scientists also say that a womb with a first time pregnancy does not have much  immunity to transfer to the first foetus; but, subsequent pregnancies let the womb build up and transfer immunity to babies born after the first.
  
  
• Being the only child --- The premise of being the firstborn is the same for the single child situation.  An over-sanitised environment or the new-womb-less-immunity situation for the only baby makes


• Gender and age -- Before and during adolescence, more boys are prone to have hay fever than girls.  After these periods, however, a lot of boys outgrow their allergy, leaving the count of affected girls higher.


• Income Level -- Babies born to families with higher incomes and higher standards of living are more at risk for developing hay fever.  Higher standards of living decrease the chances of babies to contract infections.  Somehow, people with fewer childhood infections are at greater risk of facing autoimmune problems later on.  As with the hygiene theory, the less chances the young body has to build up its immune system early in life, the more susceptible it is to allergies in the future.


• Exposure to second-hand smoke -- Infants who are constantly exposed to cigarette smoke in their first few years of life are more prone to develop allergic rhinitis in the later years.
  

Climate Change and Hay Fever

If you belong to about 500 million people worldwide suffering from hay fever, it would be good for you to know that the presence of grass pollen, a major allergen, is expected to be on the rise globally as a result of climate change.  An abstract published in 2014 on the online journal, PLOS ONE, states:  “Climate change is noticeably affecting plant, animal and human systems and is anticipated to have large impacts on human health.  A major concern is that wind-borne pollen, a primary cause of allergic rhinitis, may change in timing, amount, and allergenicity with future climate change, and may increase both the symptom severity and number of people affected.”  According to the abstract, the increased levels CO2  in the atmosphere shows that there is indeed a significant amount more of pollen travelling in the air.

As plants are sensitive to the gases in the air, the artificial increase of carbon dioxide released into our atmosphere is stimulating the earlier release of pollen and also lengthening the time of pollination. This means that the pollen season is beginning earlier than before and is becoming more prolonged than ever. What’s more, the heightened levels of CO2  increase pollen production and strengthen the allergen component in the pollen itself as well.

Climate change is indeed very bad news for hay fever sufferers.