Mugwort pollen allergy
Mugwort pollen allergy, common in autumn.
About mugwort pollen allergy
Mugwort is a common wild weed found along roadsides, waste ground and field edges across the UK and Europe. It is a leading source of weed pollen, which is released mainly in late summer and autumn, roughly from July through September, extending the hay-fever season beyond the earlier tree and grass peaks. When a sensitised person inhales the pollen, the immune system produces IgE antibodies against mugwort proteins, driving the release of histamine and allergic symptoms. Weed-pollen allergy is less common than grass allergy in the UK but is an important cause of late-season hay fever.
The usual presentation is seasonal allergic rhinitis, with sneezing, a runny or blocked nose and itchy, watering eyes in late summer and autumn, and it can worsen asthma and eczema in those prone to them. Mugwort is also associated with pollen-food (oral allergy) syndrome, sometimes as part of a "celery-mugwort-spice" pattern, where some people get an itchy mouth after eating foods such as celery, carrot and certain spices; it may also cross-react with ragweed pollen. These oral reactions are usually mild but should prompt advice if more marked.
During the season it helps to check pollen forecasts, keep windows shut at peak times, wash off pollen and avoid disturbing weeds. Diagnosis uses skin-prick or specific-IgE tests. Treatment follows the usual ladder of antihistamines and steroid nasal sprays, with immunotherapy considered for selected cases. See a GP if symptoms are hard to control or affect sleep, school or work.
Common triggers
- Mugwort pollen and products containing it
Symptoms
- Sneezing and a runny or blocked nose
- Itchy, red or watery eyes
- Itchy throat, nose or ears
- Coughing or wheezing
- Worsening of asthma
Avoidance & management
- Reduce exposure to the trigger where possible
- Keep windows closed during high-exposure periods
- Use air filtration and wash bedding regularly
- Shower and change clothes after exposure
- Use prescribed antihistamines, nasal sprays or preventers
Sources & references
Allergy safety: what everyone should know
Mild-to-moderate reaction signs
- Itching, hives or a raised rash
- Swelling of lips, face or eyes
- Tingling mouth, sneezing, runny nose
- Stomach pain, nausea or vomiting
Anaphylaxis — call 999 (UK) or 112 (EU) immediately
- Difficult or noisy breathing, wheeze, persistent cough
- Swelling of the tongue or tightness in the throat
- Dizziness, collapse, pale and floppy (young children)
- Use an adrenaline auto-injector (e.g. EpiPen) at once if prescribed, then call an ambulance even if symptoms improve
Allergy or intolerance? A true allergy involves the immune system and can escalate quickly; an intolerance (e.g. lactose intolerance) is unpleasant but not life-threatening. The symptoms overlap, so self-diagnosis is unreliable.
Getting tested: home-testing kits based on IgG are not diagnostically valid. If you suspect an allergy, ask a GP for referral to an allergy clinic for skin-prick or specific-IgE testing and a supervised food challenge where appropriate.