The information in this website is intended only for healthcare professionals. By entering this site, you are confirming that you are a healthcare professional.
Native to Europe but introduced on all continents with temperate zones, ryegrass is a short-lived perennial, biennial, or annual bunchgrass.1 Also known as ray-grass, English ryegrass, perennial ryegrass, and Italian ryegrass, it’s typically found in locales such as pastures, footpaths, sand dunes, and riverbeds.1,2 Ryegrass is wind-pollinated, and it releases an abundance of pollen during peak flowering season.3 Flowers are located on stalks that are 5 to 15 centimeters (2 to 6 inches) tall, and pollination occurs from spring to fall.4 Ryegrass is severely allergenic and is one of the most serious of a large number of grasses that cause allergic rhinitis (hay fever) and other respiratory allergies in humans.2,4
While native to Europe, ryegrass can be found on all continents with temperate zones.1 It's typically situated in locales such as pastures, footpaths, waste places, sand dunes, river beds, and roadsides.2
Many patients with ryegrass allergy can experience symptoms when exposed to other allergens such as tree, weed, or grass pollens, making it difficult to determine which pollen is causing the symptoms, especially when pollen seasons are overlapping. This is called cross reactivity and occurs when your body's immune system identifies the proteins, or components, in different substances as being structurally similar or biologically related, thus triggering a response.7 Other respiratory allergens that may cause reactions associated with ryegrass are other grasses, including wheat, along with tree and weed pollens.7
If you experience an itchy mouth or throat after eating fresh fruit or raw vegetables, you may suffer from oral allergy syndrome (OAS), sometimes called pollen food allergy syndrome (PFAS). This condition is also caused by your immune system’s reaction to similar proteins, or components, found in different allergens. It is quite common, with up to 25% of children with allergic rhinitis (i.e., hay fever) also suffering from OAS.8 Common plant foods involved in OAS for ryegrass include melon, watermelon, citrus, banana, pineapple, persimmon, zucchini, tomato, hazelnut, peanut, and many more.7
Knowing the proteins, or components, within each allergen that are triggering your symptoms can help guide your management plan. With that in mind, and based on your symptom history, your healthcare provider may suggest something called a specific IgE component test, which can help reveal other pollens and foods you may react to. Results from this test can also help your healthcare provider decide if allergen immunotherapy may reduce your symptoms.7
Already have your specific IgE component test results?
Your component test results will include the name of the components (a series of letters and numbers). Your healthcare provider will likely review the results with you, but here you’ll find an at-a-glance breakdown you can use as a reference. Simply match the component names to the list below to see what they mean in terms of symptom management.7
*These products may not be approved for clinical use in your country. Please work with your healthcare provider to understand availability.
rPhl p 1, rPhl 5b
rPhl p 7
rPhl p 12
The management of allergic rhinitis includes avoidance of relevant allergens, symptomatic treatment, and allergen immunotherapy.8,10,11
Ryegrass allergy symptoms can be similar to many other pollen allergies and may include:5,8
If you’re sensitized to ryegrass and have asthma, grass pollen may trigger or worsen asthma symptoms, such as coughing and wheezing.5,8
While symptoms are usually limited to the throat, nose, and eyes, some people who are severely allergic to grass may also develop hives (urticaria) upon contact with its pollen.6
Together with your symptom history, skin-prick testing or specific IgE blood testing can help determine if you are sensitized to a particular allergen. If you are diagnosed with an allergy, your healthcare provider will work with you to create a management plan.
While ryegrass may flower almost all summer, it usually pollinates between May and July in the Northern Hemisphere.1
Responses close to anaphylaxis have occurred in the most dangerous reaction cases.6 Plus, anaphylaxis has been reported in cases where abraded skin contacted allergenic grass.9