Common Ragweed
Allergy Facts, Symptoms, and Treatment

Featuring lacy leaves and growing to a height of roughly 1 meter (3.5 feet), common ragweed is known by a multitude of names, including Roman wormwood, hogweed, hogbrake, bitterweed, annual ragweed, blackweed, carrot weed, hayfever weed, hayweed, stammerwort, and wild tansy.^1,2,3 While native to North and Central America, common ragweed is an annual herb that has been widely distributed across the world, where it's found in disturbed locales such as construction sites as well as amid cultivated land and riverbanks.³ Common ragweed plants create enormous amounts of pollen, as a single plant is capable of producing millions of small pollen grains, which often travel long distances.⁴ Released spring to fall, the wind-borne pollen is highly allergenic and can induce allergic rhinitis (hay fever) and dermatitis.^1,3,5 In fact, 10 percent of the United States population is ragweed sensitive according to a large skin test survey.⁴

Are there other allergens I could be sensitized to?*

Many patients with common ragweed 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 common ragweed are certain grasses, trees, and weeds (e.g., birch, alder, juniper, mugwort, olive, goosefoot, etc.).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 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.⁸ Common plant foods involved in OAS for common ragweed include melon, soybean, watermelon, citrus, banana, pineapple, persimmon, zucchini, tomato, hazelnut, peanut, corn, 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

nAmb a 1  

• Indicates that symptoms may be caused by ragweed pollen or mugwort pollen.⁷
• Ragweed pollen immunotherapy may be considered.⁷

rPhl p 7

• Indicates symptoms may be caused by grass or by other pollen, e.g., from trees, grass, and weeds. Further investigation may be considered to confirm all allergy triggers.⁷
• May be associated with more severe symptoms and higher prevalence of asthma than other grass pollen allergies.⁷

rPhl p 12

• Indicates that symptoms may be caused by grass or by other pollen, e.g., from trees, grass, and weeds.⁷
• May be associated with PFAS after ingestion of fruit and vegetables such as melon, tomato, apple, and celery. Further examination may be considered.⁷

MUXF3 (CCD)

• Positive specific IgE for ragweed in combination with MUXF3 CCD (Cross-Reactive Carbohydrate Determinant) being the only positive component test indicates that the cause of symptoms may be something other than ragweed pollen.⁷

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.