01/07/2026
Allergy is derived from Greek words meaning “altered reaction.” The immune system tags a substance (a.k.a. the allergen) as an invading organism and overreacts, provoking a chain of defensive reactions in the body. Symptoms can be immediate when the body produces Immunoglobulin E antibodies (IgE), and may include tingling of extremities, wheezing, coughing, tightening of the throat, nausea, abdominal cramps, and diarrhea. Some of these reactions can be so potent that potentially life-threatening anaphylaxis can occur. When the reaction is mediated primarily by Immunoglobulin g antibodies (IgE)-as is the case in the majority of allergic reactions-symptoms can be delayed for up to three days. Delayed food reactions have been linked to not only specific physical problems such as hives, headache, and sinus and bronchial problems, but also to less obvious yet insipid conditions such as vague, chronic body pain, fatigue, anxiety, and depression.
https://www.haaswellnesscenters.com/blog/what-is-an-allergy