Sweet vernal grass Allergen Facts, Symptoms, and Treatment
Learn more about common allergic diseases, symptoms, management paradigms, and testing considerations.
Is your patient a candidate for specific IgE testing?
Get detailed information on whole allergens and allergen components.
Ready to test a patient?
Learn more about common allergic diseases, symptoms, management paradigms, and testing considerations.
Is your patient a candidate for specific IgE testing?
Get detailed information on whole allergens and allergen components.
Ready to test a patient?
Sweet vernal grass, aka buffalo grass, holy grass, and vanilla grass, is a perennial species of Eurasian origin.1 Tolerating a wide range of conditions, it's also been introduced to North America, Australia, and numerous countries, where habitats include pastures, roadsides, and lawns.1,2 Measuring roughly half a meter (20 inches) in height, sweet vernal grass is severely allergenic and is one of the more significant grass types in terms of allergy.2,3 Pollinated via wind, this perennial grass flowers in early summer.2,3 Those sensitized to sweet vernal grass typically display symptoms of allergic rhinitis (hay fever), which affects the nose, eyes, and throat. In addition, grass pollen can trigger or worsen asthma symptoms.4
Native to Eurasia, sweet vernal grass has also been introduced to numerous countries and to North America and Australia. It's often found in locations such as pastures, meadows, woodlands, roadsides, and grassy beaches.1 Given its pleasurable fragrance, it's sometimes grown as lawn grass and a houseplant.2
Many patients with sweet vernal grass 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.6 Other respiratory allergens that may cause reactions associated with sweet vernal grass are other grasses, including wheat, along with tree and weed pollens.6
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 caused by your immune system's reaction to similar proteins, or components, found in different allergens. It is quite common, with up to 25 percent of children with allergic rhinitis (i.e., hay fever) also suffering from OAS.7 Common plant foods involved in OAS for sweet vernal grass allergy include melon, watermelon, citrus, banana, pineapple, persimmon, zucchini, tomato, hazelnut, peanut, and many more.6
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.6
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.6
rPhl p 1, 5b
rPhl p 7
rPhl p 12
MUXF3 (CCD)
Test results should be interpreted by your healthcare provider in the context of your clinical history. Final diagnosis and decision on further management is made by your healthcare provider.
*These products may not be approved for clinical use in your country. Please work with your healthcare provider to understand availability.
The management of allergic rhinitis includes avoidance of relevant allergens, symptomatic treatment, and allergen immunotherapy.7,9,10
Sweet vernal grass allergy symptoms can be similar to many other pollen allergies and may include:4,7
If you're sensitized to sweet vernal grass and have asthma, grass pollen may trigger or worsen asthma symptoms, such as coughing and wheezing.4
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.5,7
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.
*These products may not be approved for clinical use in your country. Please work with your healthcare provider to understand availability.
Sweet vernal grass pollinates in the early summer.3,6
Responses close to anaphylaxis have occurred in the most dangerous reaction cases.5 Plus, anaphylaxis has been reported in cases where abraded skin contacted allergenic grass.10