Ragweed Allergy

What is a ragweed allergy?

A ragweed allergy is when you have an allergic reaction to ragweed pollen. Pollen is a tiny particle that certain flowering plants release to fertilize plants of the same species. Ragweed pollen is quite powerful — a single ragweed plant can produce up to 1 billion pollen grains.

Allergies happen when your immune system believes a substance (in this case, ragweed) is a harmful invader. It causes your body to release chemicals to fight off the allergen. These chemicals are what cause allergy symptoms to begin. Ragweed pollen causes seasonal allergy rhinitis (hay fever) and symptoms like sneezing and nasal congestion.

Ragweed packs its biggest punch in late summer and fall or from late July to early November. This is when people with a ragweed allergy can expect the most symptoms because ragweed pollen levels are high. The exact timing varies depending on where you live. It also tends to be worse from about 10 a.m. to 3 p.m. on warm, dry days.

What is ragweed?

Ragweed plants are soft-stemmed weeds. They grow wild and abundantly each year. You begin seeing them in spring, but they flower in August to September in most areas of the country. Warm, dry weather with a slight breeze creates the perfect scenario for ragweed to release pollen. Pollen from ragweed plants is very light and floats easily, sometimes up to hundreds of miles. In fact, ragweed pollen was found two miles up in the air. Ragweed grows in every state in the United States except Alaska. Ragweed allergies tend to be worse in the Eastern and Midwestern parts of the U.S.

How common are ragweed allergies?

Ragweed allergies are one of the most common of all pollen allergies. Up to 1 in 5 people in the U.S. experience some type of reaction when ragweed pollen levels are high.

What does a ragweed allergy feel like? 

If you have an allergy to ragweed, you may have the following symptoms after breathing in or touching ragweed:

• Runny nose.
• Coughing or itchy throat.
• Nasal congestion (stuffy nose).
• Itchy or watery eyes.
• Rash or hives.

If you have asthma, a ragweed allergy can cause your asthma to flare up or worsen.

Can a ragweed allergy cause cold symptoms?

Yes, a ragweed allergy causes symptoms similar to the common cold like a stuffy or runny nose and coughing.

What causes a ragweed allergy?

An allergic reaction happens when your body mistakenly thinks a substance is a foreign invader. It goes into defense mode — releasing chemicals to fight off this invader. The problem is that these chemicals cause allergy symptoms.

Who is at risk for a ragweed allergy?

You might be more likely to develop a ragweed allergy if you have a history of asthma or eczema, or if you have a family history of allergies.

What foods should people with a ragweed allergy avoid?

Certain foods contain a similar protein to ragweed pollen protein. This means you can also develop an allergic reaction to these foods because your body can’t tell the difference between the proteins. This is called oral allergy syndrome (OAS). It can cause you to develop symptoms like a tingly or itchy mouth when you eat specific foods.

Some of the foods that may trigger symptoms in people with ragweed allergies are:

• Bananas.
• Watermelon.
• Cantaloupes.
• White Potato.
• Zucchini.
• Cucumber.
• Sunflower seeds.
• Chamomile.
• Artichoke.

How is a ragweed allergy diagnosed?

Healthcare providers diagnose a ragweed allergy by reviewing your symptoms and ordering an allergy test. The most common allergy test is a scratch test. With this test, an allergist pricks or scratches ragweed pollen onto your skin. If you have an allergy, your skin will react by turning red, swelling or becoming bumpy. These tests are the most reliable and you can have your test results as early as 15 minutes after exposure to the allergen.

A blood test involves an allergist getting a sample of your blood and testing it for antibodies against ragweed pollen. Results of this type of test take a little bit longer than a skin test.

How is a ragweed allergy treated?

Medications

There are both over-the-counter (OTC) and prescription medications for allergies. Some of them are:

• Antihistamines: This type of medication blocks histamine, a chemical that your body makes in response to an allergy. This can reduce allergy symptoms. Common antihistamines are cetirizine (Zyrtec®) or fexofenadine (Allegra®).
• Nasal corticosteroids: These nasal sprays reduce inflammation and congestion. Fluticasone (Flonase®) is an example of a nasal steroid.
• Leukotriene inhibitors: This is a medication that blocks leukotriene, a chemical your body releases during an allergic reaction.
• Decongestants: This medication helps shrink your nasal passages and relieves congestion and runny nose. An example of a decongestant is pseudoephedrine (Sudafed®).
• Antihistamine/decongestant: This combines both an antihistamine and a decongestant. Claritin-D® is an example. 
• Cromolyn sodium: This is a nasal spray that blocks chemicals that cause allergic reactions.
• Immunotherapy: Your provider may prescribe allergy shots, which help your body build up a resistance to an allergen. There are also tablets that dissolve under your tongue that have a similar effect.

Be sure to discuss the side effects and risks of taking allergy medications with your healthcare provider.

Limit your contact with ragweed

Changing your lifestyle so you can avoid ragweed can also help. Here are some tips:

• Avoid the outdoors in the morning and early afternoon when pollen counts tend to be higher.
• Keep windows closed and use air conditioning or fans to cool off. Install HEPA (high-efficiency particulate air) filters for even more protection against ragweed pollen.
• Wear a face mask, sunglasses or hat when you’re outside.
• Shower after coming in from outside to remove the pollen from your clothes, skin and hair. Your pet(s) can also carry ragweed pollen on their fur.
• Don’t hang clothes outside to dry.

Track pollen counts in your area

Several weather websites and apps can tell you what the pollen levels are in your area. While most can’t tell you what type of pollen is high, they can be a tool to help manage your allergy, especially in peak ragweed season. When it predicts pollen is high in your area, try to stay inside or take precautions to avoid pollen.

What’s the best medicine for a ragweed allergy?

The best medicine for a ragweed allergy is unique depending on your body. Certain medications work well for some people, but not for others. For example, some people respond well to over-the-counter antihistamines, while others find relief from using nasal sprays.

That’s why it’s important to get a diagnosis and work with your healthcare provider on a treatment that works best for you.

Can this be prevented?

No, you can’t prevent a ragweed allergy. You can only manage symptoms.

When should I see my healthcare provider?

See a healthcare provider if you experience seasonal allergy symptoms like nasal congestion, itchy throat or cough. Ragweed allergies are extremely common in the U.S. You may have one if you experience allergies in summer and early fall.

What’s the worst state for a ragweed allergy?

The Midwest and eastern parts of the U.S. tend to be the worst for ragweed allergies, with ragweed pollen season lasting from July to November. The season is slightly shorter in southern states like Louisiana, Mississippi and Texas. States like Florida have the shortest ragweed pollen season.

A note from Cleveland Clinic

A ragweed allergy is an allergic reaction to the ragweed plant. Because ragweed pollen is so small and light, it travels easily. It can wreak havoc on people with seasonal allergies and cause nasal congestion, coughing and other unpleasant symptoms. You don’t have to suffer through summer and fall with ragweed allergies. Talk to your healthcare provider about what you can use to manage your allergy symptoms. They can find a treatment that can get you outside and enjoying the outdoors again.