Timothy Grass
Allergy Facts, Symptoms, and Treatment

The most abundant airborne grass pollen comes from tall meadow grasses such as Timothy grass, which is prevalent in temperate climates.^1,2 With aliases that include common cat's tail, herd grass, meadow cat's tail, and herd's grass, Timothy grass is a short-lived perennial that grows up to approximately 150 centimeters (5 feet) tall and features flat leaves with a dense spike-like flower cluster.^3,4 Releasing its wind-borne pollen from spring to fall, Timothy grass (Phleum genus) is among the worst grass genera that cause hay fever in early summer.^4,5 This species is second only to orchard grass in allergenicity among grasses, making it severely allergenic.⁴

Are there other allergens I could be sensitized to?*

Many patients with Timothy 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.⁹ Other respiratory allergens that may cause reactions associated with Timothy grass are other grasses, including wheat, along with tree and weed pollens.⁹

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.¹⁰ Common plant foods involved in OAS for Timothy grass include melon, watermelon, citrus, banana, pineapple, persimmon, zucchini, tomato, hazelnut, peanut, and many more.⁹

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.⁹

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.⁹

rPhl p 1, rPhl p 5b

• Indicates that the symptoms may be caused by grass pollen.⁹
• Grass pollen immunotherapy may be an option.⁹

rPhl p 7

• Indicates symptoms may be caused by grass or by other pollen, e.g., from trees and weeds. Further examination may be considered to confirm all allergy triggers.⁹
• May be associated with more severe symptoms and higher prevalence of asthma than other grass pollen allergies.⁹

rPhl p 12

• Indicates that symptoms may be caused by grass or by other pollen, e.g., from trees and weeds.⁹
• May be associated with PFAS after ingestion of fruit and vegetables, e.g., melon, tomato, apple, and celery. Further examination may be considered.⁹

MUXF3 (CCD)  

• Positive specific IgE for Timothy grass in combination with MUXF3 (CCD) being the only positive component test indicates that the cause of symptoms may be something else than grass pollen.⁹

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.