Durban — Hormonal changes, infections or changes in the immune system can trigger new food allergies in adults. This is according to the CEO of the Allergy Foundation of South Africa (AFSA), Professor Mike Levin.

Levin was speaking ahead of World Allergy Week which takes place from June 23–29, and the theme for this year is food allergies, which are said to be reaching epidemic levels.

He said this phenomenon is known as adult-onset food allergies and it can occur with foods previously eaten without any issues.

Levin said while food allergies are often associated with children, adults can also develop new allergies later in life. Moreover, he said many people with pollen allergies, such as hay fever, may experience oral allergy syndrome (OAS) when eating certain fruits, vegetables and nuts.

“This happens because the proteins in these foods are like pollen proteins, causing the immune system to react. For example, individuals allergic to birch pollen might react to apples, carrots, and celery,” said Levin.

He added that in some instances physical exercise can trigger an allergic reaction to a particular food if consumed before exercising. According to AFSA, this condition, known as exercise-induced anaphylaxis, can be severe and is often linked to foods such as wheat, shellfish and celery.

“Avoiding exercise for a few hours after eating the trigger food can help manage this condition.”

Levin said food allergens can be found in unexpected places, making it crucial to read labels carefully.

“For instance, peanut oil might be used in cosmetics and wheat proteins can be found in some medications and even in craft supplies like play dough,” he warned.

He further said that cross-contamination during food processing is also a concern as trace amounts of allergens can be present in seemingly safe foods.

Professor Claudia Gray, a paediatrician and allergologist at the Kids Allergy Centre and an allergy consultant at the Red Cross Children’s Hospital, advised that the prevalence of food allergies, particularly in children, has risen steadily over the past few decades.

“While the exact cause is not fully understood, factors such as changes in diet, environmental influences, and the ‘hygiene hypothesis’ – which suggests that a lack of early childhood exposure to germs affects the immune system – are being investigated as potential contributors.”

Gray further stated that there is a strong link between food allergies and asthma.

“Children with food allergies are more likely to develop asthma, and having both conditions increases the risk of severe allergic reactions. Proper management of both asthma and food allergies is essential to reduce the risk of life-threatening anaphylactic reactions.”

Independent on Saturday