Allergy is a misguided reaction to foreign substances by the immune system. Human body is having defense against foreign invaders, particularly to pathogens. Generally allergic reaction is misguided to these foreign substances, which are usually harmless. Elm trees are a major source of allergy. Tree pollens that trigger allergies tend to be very fine and powdery. The wind can carry them for miles. Inhaling even small amounts can trigger allergy symptoms. Symptoms of ELM tree pollen allergy include Low grade fever, Sneezing, runny nose, itchy nose, watery eyes, itchy skin, sore throat, poor appetite, frequent headaches. Allergic reaction to tree pollen may cause mental dullness and fatigue