Pollen allergies are becoming more common and appearing earlier

Allergic diseases are becoming more common, and pollen allergies can now appear in children as young as one or two, allergologist Kaja Julge told ERR. An estimated one in three people has experienced allergy symptoms at some point in life.

Allergies can develop at any age and may also recede, but they do not indicate a weak immune system. Rather, the immune system reacts in an imbalanced way to substances that it should not normally respond to, Julge said on Vikerraadio’s Huvitaja programme.

Researchers are examining the reasons for the increase in allergies. In addition to air pollution and other environmental factors, increasing attention is being paid to how the immune system functions and to the gut microbiome.

Studies of Estonian and Swedish children conducted in the early 1990s showed that the intestinal flora of children with atopic dermatitis differed from that of Swedish children. According to Julge, food affects the composition of microbes, while the microbes influence the immune system.

“Microbes are what teach our immune system to behave correctly,” Julge said, adding that the immune system needs contact with the surrounding environment to learn. She compared this to learning to swim, which cannot be done on dry land, saying the immune system likewise cannot be trained in sterile conditions.

Allergies can appear in different ways, depending partly on age. In young children, eggs, milk, wheat, soya and nuts can commonly trigger reactions. Egg and milk allergies often recede with age, while sensitivity to airborne allergens such as pollen, dust mites or animals may develop.

“Genes provide the predisposition, while the environment affects whether the allergy manifests itself,” Julge said. Allergies can also change from one form to another. For example, a person with a pollen allergy may develop a cross-allergy, in which the body also begins reacting to certain foods.

Allergy and intolerance are different

Food allergy and food intolerance are two different conditions. Allergy involves the immune system, while intolerance has a different cause. Lactose intolerance is one of the most common intolerances.

Another important difference concerns the amount that triggers a reaction. In the case of an allergy, a very small amount of an allergen can cause a reaction.