For some people, a warm winter like this one means that allergy season is hovering. A few years ago, with no warning, one of my boys started suffering from seasonal allergies. He asked me why he suddenly became allergic, and why he wrestles with allergies and his siblings do not.

Although his siblings do not share his misery, my son is not alone: It is estimated that about 50 million Americans fight seasonal allergies. An allergy is essentially the immune system reacting, or overreacting, to a trigger. Triggers can be something in the environment, such as mold or pollen, or a food we eat, such as peanuts or eggs.

There are many factors that can cause someone to suffer from allergies, and the science isn’t precisely understood. It also doesn’t help that everyone’s body is different. According to “The Allergy Solution” by Leo Galland and Jonathan Galland, factors that contribute to the immune system’s sensitivity to allergens can include environmental toxins in the air, the overuse of antibiotics, an overly sterile early childhood and a changing food system that can cause internal inflammation and nutrient deficiencies.

Certain people’s immune systems may be triggered more easily because of a genetic predisposition or another factor. “All classic allergies are triggered by the immune system, anything that harms the immune system can contribute to allergies,” Kenneth Bock writes in his book “Healing the New Childhood Epidemics.”

Because 70 percent of the immune system is found in the digestive tract, it is no wonder that the foods we eat either contribute to or counteract immune function.

My kids grasped that certain foods could trigger an allergic reaction, and that pollen, fertilizers and other outdoor pollutants could be culprits, but they were surprised that our electronics and carpets shed chemicals that end up annoying our immune systems. According to the Environmental Working Group, flame retardants are one big offender because they are in many consumer products, such as telephones, televisions, sofas, toys and basketballs.

Over time, allergies can lead to other health issues that don’t look or feel like allergies, such as fatigue, muscle aches, sleep issues and bodywide inflammation, so it is wise to handle them when they present themselves. There are many nonmedical methods that support the immune system and could help keep allergies in check.

advertisement | advertise on newsday

Casey Seidenberg is co-founder of Nourish Schools, a Washington, D.C.-based nutrition education company, and author of The Super Food Cards.’’