Grass (General)

Grass pollen is the most common cause of allergic rhinitis (hay fever) worldwide. The major allergenic grasses include Timothy, Bermuda, Kentucky Bluegrass, Ryegrass, and Fescue. Unlike trees that bloom for a few weeks, grass pollen season can last for months. Grass pollen grains are moderately sized and highly allergenic — the allergens are concentrated on the surface of the grain and are released immediately on contact with mucous membranes.

If you're allergic to grass (general) pollen, you may also react to:

• Wheat, rye, barley, oats (cereal grains are grasses)
• Tomatoes, potatoes (in some individuals)
• Melons, oranges (limited)
• All grasses cross-react with each other significantly

• Mowing the lawn releases massive amounts of grass pollen. If you're allergic, have someone else mow or wear an N95 mask.
• Grass pollen peaks in the morning and on warm, windy days. Late evening is the best time for outdoor activities.
• All grasses cross-react, so you can't avoid grass allergy by avoiding specific grass species.
• Rain washes pollen from the air but also causes pollen grains to burst, releasing smaller allergenic particles. Symptoms can spike after thunderstorms ('thunderstorm asthma').
• Sublingual immunotherapy (allergy tablets) for grass pollen is FDA-approved and can be done at home.