Did you know that bird’s nest was once the biggest cause of anaphylaxis in Singapore? While that has changed over the years, food allergy is still the most common trigger for anaphylaxis, accounting for over 40% of ER visits (insect stings come in second). Food allergies may not be uncommon, but did you know that other things – like sunlight and ever exercise – can also cause anaphylaxis?
Severe food allergies
Last year, a woman died from eating 2 pieces of prawns, and a toddler had a near-death experience when packets of peanuts were opened in the airplane cabin he was in. Anaphylaxis is a potentially life-threatening condition which can result in anaphylactic shock, when your blood pressure plummets and you have difficulty breathing.
In terms of foods, adults in Singapore are most allergic to:
- shellfish (accounts for more than half of anaphylaxis)
- tree nuts
- birds nest
Peanut allergy is now the most common cause of anaphylaxis in children.
Tingling in the mouth or swelling on the tongue?
The most common sources are fruits – especially kiwi, as well as pineapples, avocados, bananas, apples and carrots. This are either caused by a certain protein in these fruits, or pollen allergy.
Wheezing and rashes
Galacto-oligosaccharide (GOS) allergy is a relatively recent phenomenon unique to Singapore and other SEA countries. GOS is a prebiotic found in most milk products in Asia to promote the growth of good bacteria in the gut. Allergic reaction (from wheezing to rashes) to GOS could take from minutes to hours within ingestion for symptoms to appear, and is more common in those with allergies like eczema or asthma.
Exercise-induced anaphylaxis is rare, but it’s real, not an excuse to skip PE. It’s often difficult to diagnose as the symptoms include itchy skin, swelling in the eyes or mouth, difficulty breathing, and abdominal issues – most people may put it down to the lack of fitness or an asthmatic attack.
More common is food-dependent exercise-induced anaphylaxis, which is a reaction to exercising before or after eating certain foods. In Singapore, that trigger food is usually wheat or prawns, even though eating those foods alone doesn’t cause any reaction. To be safe, don’t exercise 2-4 hours before or after eating these foods.
Sun allergy is real – like vampires, people with this condition will develop and itchy rash when their skin is exposed to the sun. About 10-20% of the population have this affliction. There are a few variants of this allergy, and most commonly affect young women.
Polymorphous light eruption is a skin rash that occurs within hours to a day of sun exposure, and persists in the first 3 decades of life. Solar urticaria causes hives to erupt within a few minutes of exposure to the sun (or artificial light); this rare condition is sometimes treated with antihistamines, or in extreme cases, phototherapy or anti-IgE treatment.