Ragweed allergy
Grass season is over, but you are still sneezing in late August? Ragweed is a late-flowering weed whose pollen is a strong trigger, and it is spreading in Europe. Our test checks for IgE sensitisation to ragweed as part of 300 allergens and allergen components, so you can see it next to mugwort and grass rather than guessing.
- Group
- Pollen
- Season
- Roughly August to October in central Europe, peaking in late August and September
- Also known as
- ragweed allergy, Ambrosia artemisiifolia, common ragweed, Amb a 1
Where you meet it
- Roadsides, building sites, railway lines and field edges
- Gardens under bird feeders, as seeds travel in birdseed
- Fields of sunflowers and maize, where it grows as a weed
- Air several hundred kilometres from the plants on windy days
What ragweed is
Common ragweed (Ambrosia artemisiifolia) originally comes from North America. In Europe it is now widespread in Hungary, northern Italy, south-east France and the Balkans, and has been spreading north into Germany and Austria.
A single plant can release very large amounts of pollen, and small amounts are enough to cause symptoms in sensitised people. Its main allergen is called Amb a 1.
What people commonly report
Ragweed symptoms look like any other hay fever, just later in the year: sneezing, runny or blocked nose, itchy eyes. Some people notice chest symptoms such as coughing or wheezing.
The timing is the clue. If spring and early summer are fine but late summer is not, ragweed and mugwort are the first two to check.
- Sneezing and runny nose from mid-August
- Itchy, watery eyes into September
- Cough or tight chest on high-count days
Ragweed, mugwort and food
Ragweed and mugwort belong to the same plant family (Asteraceae), and some people are sensitised to both. Their main allergens differ, so one does not automatically mean the other.
Some people sensitised to ragweed report itching in the mouth after eating melon or banana. This association is described in the literature, but it is less common than the birch and apple link.
How the test checks ragweed
Your finger-prick sample is tested for IgE to ragweed pollen as part of 300 allergens and allergen components. Mugwort, grasses and trees are on the same panel, which helps separate a late-summer pattern from a spring one.
A positive result means sensitisation, not a confirmed allergy. Each value gets a class from Negative to Very high, a pattern to take to a doctor, who decides what it means for you.
- Whole ragweed pollen extract
- Amb a 1: the main ragweed protein, specific to ragweed
- Amb a 4: a ragweed protein related to mugwort's Art v 1
Known cross-reactions
- Mugwort
- Same plant family and the same late-summer season. Many people are sensitised to both, though their main allergens are different.
- Melon and banana
- An association reported in some ragweed-sensitised people, usually as itching in the mouth after eating them raw.
Sources
- Ragweed Pollen Allergy: Burden, Characteristics, and Management of an Imported Allergen Source in Europe. International Archives of Allergy and Immunology, 2018.
- Climate Change and Future Pollen Allergy in Europe. Environmental Health Perspectives, 2017.
- Marker allergens of weed pollen: basic considerations and diagnostic benefits in the clinical routine. Allergo Journal International, 2014.
Page last updated
300 allergens. One test.
A finger-prick sample at home, sent by post. A detailed lab report typically 5 days after the lab receives your sample, and our plain-English guide to reading it. €300, €1 per allergen.
Questions
When is ragweed season?
In central Europe ragweed usually flowers from August to October, with the most pollen in late August and September. Its pollen can travel long distances, so you may be exposed even where the plant is rare.
Does ragweed grow in Germany?
Yes, in a growing number of places, often along roads and on disturbed ground. Higher concentrations are found in parts of Hungary, northern Italy and south-east France, and pollen from there can reach central Europe on the wind.
Is ragweed the same as mugwort?
No. They are related plants that flower at similar times, which is why they are easy to confuse. The test measures sensitisation to each separately.