A grass allergy is an immune system reaction to airborne grass pollen. This releases chemicals like histamine. While everyone breathes in grass pollen, not everyone experiences an allergic reaction. It is a common trigger for seasonal allergic rhinitis, often known as hay fever.
Prevalence of Grass Allergy
Grass pollen allergy is one of the most common causes of seasonal allergy symptoms globally. In the United States, hay fever, largely due to pollen allergies, affected 19.2 million adults and 5.2 million children in 2016. Grass pollen is microscopic, light, and easily carried by wind, often traveling long distances.
Grass pollen season often causes symptoms from late spring to early summer, from April through early June in northern regions. However, in warmer climates like the southern U.S., grass can pollinate year-round due to milder winters and extended growing seasons. This can lead to symptoms persisting for many months or even throughout the year.
The intensity and duration of grass pollen season may be influenced by climate change, with some evidence suggesting longer growing seasons and higher amounts of grass pollen. While hundreds of grass types exist, only a few commonly trigger allergies. These include Timothy, Ryegrass, Bermuda, Kentucky Blue, Orchard, Johnson, Fescue, Sweet Vernal, and Bahia grasses. The specific types that cause symptoms can vary by geographical location.
Identifying and Managing Grass Allergy
Grass allergy symptoms involve the nose, eyes, and throat. People often experience sneezing, a runny or stuffy nose, and postnasal drip. Eye symptoms include itchiness, redness, and watery eyes, sometimes accompanied by swelling. Other symptoms are a scratchy throat, coughing, headaches, and fatigue.
Diagnosis of a grass allergy involves a healthcare provider asking about medical history and symptoms. If an allergy is suspected, an allergist may perform a skin prick test, applying a small amount of grass pollen extract to the skin. Alternatively, a blood test, known as a specific IgE test, can measure the immune system’s response to specific grass pollens.
Managing grass allergy symptoms involves a combination of exposure reduction and medication. Monitoring local pollen counts and staying indoors during peak times, especially between 5 a.m. and 10 a.m. or on windy days, helps. Keeping windows closed in homes and vehicles, showering after outdoor activities, and changing clothes can reduce pollen exposure. Wearing a mask while doing yard work also helps filter out pollen.
Over-the-counter medications provide relief. Oral antihistamines like cetirizine, loratadine, and fexofenadine alleviate sneezing, runny nose, and itchy eyes. Corticosteroid nasal sprays, such as fluticasone, reduce inflammation in nasal passages and address congestion, itching, and sneezing. Decongestants may also help with nasal stuffiness, but they are for short-term use. If symptoms persist for more than two weeks, over-the-counter medications are not effective, or if asthma symptoms worsen, seek medical advice from a healthcare provider or allergist.