Why is severe allergy life-threatening and why is there a surge in food allergies worldwide?

BEIJING, Sept. 18 ,
Taiwan
United News Network reported that in recent decades, the global food
allergy
cases have increased significantly, the current
B.UK
7% of children affected by food allergies,
Australia
9%. Across Europe, 2% of adults are allergic to certain foods. Researchers around the world are trying to find ways to combat the phenomenon.
allergies are reported to be caused by a substance that the body's immune system fights against the outside world. Symptoms of allergic reactions include redness, swelling, urticaria, etc., and in severe cases can lead to vomiting, diarrhea, breathing difficulties and anaphyloic shock, and may even be life-threatening.
food allergies have increased significantly over the past 30 years, especially in developed industrialized societies. The most common foods that cause allergies in children include milk, eggs, peanuts, tree nuts, sesame seeds, fish, and shellfish.
there is no single explanation as to why more people are allergic to food around the world, but academics point to the following possibilities.
environmental factors change the way the immune system reacts
in addition to increased awareness of allergies and increased ability to diagnose allergies, environmental factors may also be the cause of increased allergy rates.
developing countries have lower allergy rates and are more likely to occur in urban rather than rural areas, possibly due to pollution, dietary changes and reduced exposure to microorganisms. These factors change the way the immune system reacts.
addition, the incidence of asthma and food allergies among migrants appears to be higher than in their countries of origin, further illustrating the importance of environmental factors.
"opponents" are fewer Immune systems attack harmless substances
the researchers note, improved hygiene reduces children's chances of getting infected, especially parasite infections. As the number of parasites to deal with decreases, the human immune system turns to what would otherwise be harmless.
lack of anti-allergic vitamin D
causes allergies is a lack of vitamin D. Currently, the majority of the world's population does not have access to adequate vitamin D for reasons including inexperied sun exposure, and the rate of vitamin D deficiency in the United States has almost doubled in the past decade.
other studies suggest that proper feeding of food to children during weaning can prevent allergies. According to a study by King's College London, babies are 80 per cent less likely to be allergic to peanuts by the time they are born.
there is no cure for food allergies. People should try to avoid foods that cause allergies and seek medical attention quickly when allergies occur.