What is mugwort allergy?

Close-up of mugwort in flower – the pollen of this weed is a common cause of hay fever in late summer and fall

Your first question might actually be, what is mugwort? It sounds like an ingredient for a Harry Potter potion. But this is a real weed and a really bothersome one. Mugwort is invasive, turning up where it isn’t wanted. And mugwort allergy gives a lot of people hay fever

Read on to find out more about:

  • Why mugwort allergy happens
  • Signs and symptoms to look out for
  • Getting a diagnosis
  • How to manage your condition

You don’t have to put up with your mugwort allergy symptoms. Everyone has options.

Mugwort allergy: the short version

Mugwort or Artemisia vulgaris releases its pollen in a peak from late summer into fall. Breathing in the flying particles can cause allergy symptoms like coughing, sneezing and a runny nose. Avoiding them means avoiding mugwort pollen. Your healthcare provider will tell you about drug-free relief and your treatment options.

Signs and symptoms of mugwort allergy

Allergy is when your immune system mistakes a harmless substance or allergen like mugwort pollen for something that can harm your body.

What’s it like to have mugwort allergy?

Mugwort allergy symptoms can feel just like a cold. Both are forms of rhinitis, although a runny nose from pollen allergy is likely to produce clear mucus whereas yellow mucus is typical of a cold. And you already know the impact a persistent cold can have on your life…

You may find your sleep is affected, leaving you feeling exhausted the next day. Allergic rhinitis (hay fever) can make it hard to concentrate at work or school – and may even mean taking time off. And you might not be able to take part in the outdoor activities you enjoy.

When and where is mugwort allergy worst?

Geography plays a big part in this. It will depend very much on where you live or travel to most often.

Bathroom cabinet with a white cross on a mint green circle on the half-open door, ready to hold your allergy medicine

Simple guide to
allergy medicines

Mugwort allergy season

Mugwort has spikes of pale little flowers on a stem over 3ft tall. Each of these mugwort flowers produces up to 16,000 pollen grains, which it releases in late summer and fall. The exact timing varies but this is the general time of year you’re most likely to get allergic rhinitis.

Mugwort pollen hotspots

Also known as chrysanthemum weed or common wormwood, mugwort is a common cause of weed pollen allergy. The plant is fast-spreading, invasive and widespread, except in the far north and south.

Think of the places you mostly don’t go to: garbage dumps, roadsides or where buildings have been demolished. That’s where mugwort tends to grow and there’s likely to be a high concentration of its pollen in the air. nbsp;It doesn’t seem to travel as far as other weed pollen. For instance, ragweed pollen can make people sneeze hundreds of miles from where it grows. These two plants are cousins and sometimes mistaken for each other.

Mugwort allergy symptoms from other plants

This is called a cross-reactivity. Proteins are what stimulate the allergic response from your immune system. Other types of pollen allergens can be similar to mugwort proteins and have a similar effect on you.


Oral allergy syndrome affects around one in four people with mugwort allergy. You may get an itchy mouth or throat, or swollen lips and tongue, when you eat certain plant foods.

Related plants can give you hay fever

People who are allergic to mugwort may get symptoms from other types of artemisia pollen and from members of the wider daisy (Asteraceae) family. If sunflower, cocklebur, marsh elder or ragweed pollen make you sneeze, you could be having a cross-reaction.

So can trees and grass

Birch pollen and Timothy grass pollen can also confuse your immune system into reacting if you have mugwort allergy. This could mean your seasonal respiratory symptoms drag on for longer because birch pollen is in the air in spring and grass pollen during summer.

Mugwort allergy and food sensitivity

Cross-reactions can also happen with food allergens. That’s different from a simple food allergy. Your body reacts to proteins in some plant-based foods because they’re similar to those in mugwort pollen. It’s called oral allergy syndrome (OAS), pollen food syndrome (PFS) or pollen food allergy syndrome (PFAS).

Oral allergy syndrome (OAS) affects around one in four people who have mugwort allergy. 

Plant-derived foods linked to mugwort

Mugwort allergy can cause mild local symptoms from eating apples, mango, kiwi fruit, legumes, lettuce, camomile, sunflower seeds, poppy seeds, peanuts, pistachio, hazelnut, almonds and other nuts, and beer. Also honey and royal jelly.

Some mugwort-related pollen food syndromes even have their own name:

  • Mugwort mustard allergy syndrome (MMAS) can be serious and cause severe allergic reactions (anaphylaxis).
  • Celery-carrot-mugwort-spice syndrome (CCMS) means you can react not only to celery and carrot but also to spices such as anise, fennel, coriander and cumin.
  • Mugwort-peach association (MPA) and mugwort chamomile association (MCA) can also cause reactions.

Not a food allergy
but linked to pollen...

Woman holding up a juicy pink slice of watermelon and biting her lip – it could give her a tingly mouth if she has hay fever

Symptoms of oral allergy syndrome

OAS symptoms are usually mild. You might get an itchy swollen mouth, scratchy throat and swollen lips and tongue. But some cross-reacting allergens can trigger food-induced anaphylaxis. That can be life-threatening. Milder reactions may also be an early warning sign of food allergies, some of which, such as nut allergies can be more dangerous. See your healthcare provider right away if you have any food allergy symptoms.

How do I know if I’ve got mugwort allergy?

You might recognize the symptoms of a pollen related allergy and sneeze a lot during mugwort pollen season. But other weed pollen allergies can strike in late summer and early fall. Cross-reactions can also confuse things. So talk to your healthcare provider. They’ll ask you about your medical history and any allergies in your family and may suggest allergy tests before making a diagnosis.

Mugwort allergy testing

A skin prick test is usually the first step. The allergist or clinic staff will put drops of liquid containing different allergens onto your skin and gently prick it. In skin prick tests, an itchy bump after 15-20 minutes is a positive result.

There are also allergy blood tests. These look for mugwort pollen IgE reactivity. Component blood tests are more detailed. They can show which major mugwort pollen allergen you may be allergic to. It may be one that can cross-react with plant foods and even, like lipid transfer protein, cause severe symptoms.

It is possible to be sensitized and have IgE antibodies in your blood but not experience allergic reactions. Even though the immune system is primed for attack, it doesn’t act. We don’t know why this happens in some people. Having an allergy means you are both sensitized and experience an allergic reaction.

Your healthcare provider will interpret the results for you.

Managing mugwort allergy after your diagnosis

We mentioned some options right at the start. There four main ways to manage mugwort allergy and its symptoms:

  • Avoid mugwort pollen (you’ll find some tips on how to do that a bit lower down)
  • Tackle your symptoms with drug-free remedies
  • Try allergy medication if you need it
  • Ask about long-term treatment
klarify allergy app
Put our smiley icon on your homescreen. It’s a smart way to manage hay fever, with up to date pollen info for where you are and tips tailored to you.
Klarify app

Become a mugwort pollen expert

Downloading the klarify app is a good place to start. It helps you track daily pollen levels, the weather and air quality in your area. Wind, humidity and rain are the most important factors affecting the amount of pollen in the air. For example, pollen counts tend to go up on dry windy days.

Allergy is not the same for everyone. You may get symptoms when there’s a low count or feel fine even though the count is high. Our app lets you log how you're feeling each day and the smiley icon on the homescreen will adapt to show you a personalised pollen score. You’ll know if it’s likely to be a sneezy day or not.

There’s also a pollen forecast on our website. Check it every morning and then decide whether it’s a day to stay home or take symptom-relieving medication before you go out.

Tips for avoiding mugwort pollen

1. Learn how to recognize mugwort so you can give it a wide berth (there’s a picture at the top of this article)

2. Avoid going out at times of day when plants release most pollen; that is, in the morning and early evening

3. Keep windows and doors closed when pollen levels are high. Consider turning on the air conditioning instead, if you have it, to make life more comfortable

4. Wraparound sunglasses, a hat, face mask, hay fever nasal filter or cellulose spray may help keep mugwort pollen out of your eyes, nose and throat.

5. Clean regularly to keep your house free of mugwort pollen. Use a damp cloth and a vacuum cleaner with a HEPA filter

6. Keep coats and shoes by the front door so you don’t bring as much pollen into your main living space

7. Shower before bed and rinse pollen out of your hair

8. Wash clothes and bed linen regularly and dry your laundry indoors when mugwort pollen levels are high

9. Pets can pick up pollen so shouldn’t sleep in your bedroom.

Dust mite allergy: Indoors
and year-round

Stuffed toys and pillows on a child’s bed – places where dust mites live and can trigger allergy symptoms

Drug-free remedies for mugwort allergy

Saline is a simple way to ease a stuffy nose or itchy eyes. You can buy a nasal spray or eye drops over the counter at the pharmacy. A saline nasal spray rinses out allergens and you can use it alongside your usual allergy medication. In fact, it may make symptom-relievers like antihistamine more effective.

Mugwort pollen allergy medication

Allergy symptoms are a sign your body is defending itself. Feeling phlegmy and congested? Your body is making more mucus to get rid of the mugwort pollen from your nose. Watery eyes are a similar thing. And that itch is probably to get you to rub mugwort pollen off your skin.

Much of what you’re feeling is caused by histamine, a chemical released as part of allergic reactions. Antihistamine can help block its effects. Corticosteroids are another common symptom-reliever. They mimic hormones made by your body and are anti-inflammatory. Decongestants deal with a stuffy nose (but you should only take them for a limited time).

Ask your pharmacy or healthcare provider for advice. They may suggest taking them from a couple of weeks before the pollen season.

Long-term treatment for mugwort allergy

There is no cure for mugwort pollen allergy yet. But it may be possible to reduce your symptoms and the need for hay fever medication.

Your healthcare provider or allergist can talk you through the pros and cons of allergy immunotherapy (AIT), also known as desensitization. There are possible side effects, as with many medicines. And this long-term treatment isn’t suitable for everyone.

We can help you find an allergist if you need one.

We’re here for you
We hope that you have found this article about mugwort allergy helpful. Send us an email If you have any questions or want to share your story. You can also follow klarify on Facebook or Instagram.
klarify takes allergy science and makes it simple, and we have rigorous process for doing this. We use up-to-date and authoritative sources of information. Medical experts review our content before we share it with you. They and the klarify editorial team strive to be accurate, thorough, clear and objective at all times. Our editorial policy explains exactly how we do this.