Grass pollen is known to cause a variety of different allergic reactions. Grass pollenis present in the air in the late spring and early summer months, which can cause allergic rhinitis, allergic conjunctivitis and asthma. Direct skin contact with grass, from sitting in the grass or mowing the lawn, can cause itching of the skin -- urticaria and atopic dermatitis. Grass allergy can also be associated with the fruit pollen syndrome resulting in food allergies to tomatoes, potatoes and peaches.
Grasses can be divided into two major classes: northern and southern grasses. Northern grasses are common in colder climates, and include timothy, rye, orchard, sweet vernal, red top and blue grasses. Southern grasses are present in warmer climates, with Bermuda grass being the major grass in this category. Most people with significant grass allergy are allergic to most, if not all grasses, on allergy testing, because grass pollens have very similar proteins that cause allergies.