By Annaliese Jones
Do you suffer from an allergy? With the incidence of allergies doubling in western countries during the past 25 years, you are not alone. Whether it’s to peanuts or pollen, allergies affect one in three New Zealanders at some time in their lives.
The immune system – our microscopic defense force
Our immune system is really quite amazing. Like a well-trained military unit, our immune cells identify and destroy foreign invaders, even remembering past invaders for decades in case they call again. When it functions properly, the immune system monitors the entire body seeking out and destroying bacteria, viruses and toxins, it can even identify cells that may be destined to become tumours.
As incredible as this is, our immune system can make mistakes. An allergic immune system misidentifies a substance like pollen or wheat as harmful when it’s actually quite innocuous. It then attacks that perceived threat with such ferocity that you may experience hives, eczema, asthma or in extreme cases, life threatening anaphylaxis. All this caused by the same immune system that is actually trying to protect us.
How allergies work
Allergies are essentially when the immune system causes damage to the body trying to ‘fight’ off an otherwise harmless substance. The first time the immune system encounters the allergen, no symptoms occur, but unbeknown to you, sensitsation is happening. Sensitisation involves a complicated cascade of immune cell activities that eventually lead to the production of antibodies to this allergen. At the next encounter, the immune system is primed to react with histamine and other inflammatory chemicals, leading to the symptoms of allergy.
Risk factors
Why are you allergic? The biggest risk factor for allergies is one we cannot control: heredity. If your mother, father or sibling suffers from an allergy, you have a greater risk. If both parents are allergy sufferers, unfortunately your chances of being allergy free are pretty slim. Additionally, babies born in spring months are more likely to have hayfever later in life. Possibly something to consider when planning a family?!
Some types of allergies
Respiratory
Breathing is something most of us take for granted. We take over 20,000 breaths every day, to breathe is to live. But for many allergy sufferers, breathing is a struggle, through constricted lungs or congested sinuses. The respiratory system and lungs are in constant contact with the outside environment, coming across airborne allergens with every breath. No wonder then, that our body keeps a lot of immune cells in this area, ready to respond in the case of emergency. For those with allergic immune systems this means hayfever and asthma in response to pollens, animal fur or mould, otherwise harmless substances.
Food
‘Let your food be your medicine and your medicine be your food’. What about when food becomes your body’s worst enemy? The consequences of food allergies range in severity from life threatening to annoying, and the range of food one can be allergic to is huge. Figuring out what you or your baby is allergic to can be difficult because we hardly ever eat one food on its own. The most common food allergies are: eggs, milk, peanuts, shellfish, soy, tree nuts, and wheat. Food allergies frequently start in young children and may be outgrown by the age of 5, but peanut, shellfish and tree nut allergies tend to stick around for the long haul. Many people believe they have food allergies when in fact they have a food intolerance. Differentiating between the two can be difficult but usually a food allergy is much more severe.
Hives
Hives are welt-like swellings anywhere from a mosquito bite to a dinner plate in size. They frequently come up after contact with animals or certain plants, after eating certain foods or taking medication. Hives generally last a few days to a few weeks and usually resolve on their own. Avoidance of the offending substance is the only cure, and unfortunately sometimes the offending substance remains a mystery. Spicy food, heat, aspirin and alcohol tend to aggravate hives.
Extreme cases
Some people are so sensitive to a substance that their body has a life threatening reaction when it comes into contact with it. This is called anaphylaxis. The symptoms range from difficulty swallowing and breathing, to stomach cramps and dizziness, generally always causing anxiety and panic in the sufferer. Their blood pressure often drops dangerously low, causing fainting. Common causes include food allergies, drug allergies and insect bites and stings. Those who know they have anaphylaxis should always carry medication (usually epinephrine) in case of emergency. If you are around someone having an anaphylactic reaction, help them take their medication and call emergency services. Don’t assume the medication is enough. Children in daycare or school should always have access to medication. Peanut free schools, although unpopular with some parents, are a godsend to parents of severely allergic children. Imagine taking your child to kindy, school, or even just to a friend’s place and being terrified they might come across their allergen, and end up in hospital.
See next page for prevention tips plus more on children and allergies…
