Pollen Allergy

What Is a Pollen Allergy?

Pollen is one of the most common triggers of seasonal allergies. Many people know pollen allergy as “hay fever.” Experts usually refer to pollen allergy as “seasonal allergic rhinitis.”

Each spring, summer and fall, plants release tiny pollen grains to fertilize other plants of the same species. Most of the pollens that cause allergic reactions come from trees, weeds and grasses. These plants make small, light and dry pollen grains that travel by the wind.

Grasses are the most common cause of allergy. Ragweed is a main cause of weed allergies. Other common sources of weed pollen include sagebrush, pigweed, lamb’s quarters and tumbleweed. Certain species of trees, including birch, cedar and oak, also produce highly allergenic pollen.

Plants fertilized by insects, like roses and some flowering trees, like cherry and pear trees, usually do not cause allergic rhinitis.

Ragweed is the most common weed allergy

What Is a Pollen Count?

A pollen count is how much pollen is in the air. This is often reported during pollen season on local weather forecasts. Sometimes the main types of pollen are also reported.

What Are the Symptoms of Pollen Allergy?

People with pollen allergies only have symptoms when the pollens they are allergic to are in the air. Symptoms include:

• Runny nose and mucus production

• Sneezing

• Itchy nose, eyes, ears and mouth

• Stuffy nose (nasal congestion)

• Red and watery eyes

• Swelling around the eyes

How Do Doctors Diagnose Pollen Allergy?

Doctors use two tests to diagnose a pollen allergy.

Skin Prick Test (SPT)
In prick/scratch testing, a nurse or doctor places a small drop of the possible allergen on your skin. Then the nurse will lightly prick or scratch the spot with a needle through the drop. If you are allergic to the substance, you will develop redness, swelling and itching at the test site within 20 minutes. You may also see a wheal. A wheal is a raised, round area that looks like a hive. Usually, the larger the wheal, the more likely you are to be allergic to the allergen.

A positive SPT to a particular pollen allergen does not necessarily mean that a person has an allergy. Health care providers must compare the skin test results with the time and place of a person’s symptoms to see if they match.

Specific IgE Blood Test 
Blood tests are helpful when people have a skin condition or are taking medicines that interfere with skin testing. They may also be used in children who may not tolerate skin testing. Your doctor will take a blood sample and send it to a laboratory. The lab adds the allergen to your blood sample. Then they measure the amount of antibodies your blood produces to attack the allergens. This test is called Specific IgE (sIgE) Blood Testing. (This was previously and commonly referred to as RAST or ImmunoCAP testing.) As with skin testing, a positive blood test to an allergen does not necessarily mean that an allergen caused your symptoms.

How Can I Prevent an Allergic Reaction to Pollen?

There are actions you can take to reduce allergic reactions to pollen:

  • Limit your outdoor activities when pollen counts are high. This will lessen the amount of pollen allergen you inhale and reduce your symptoms.  
  • Keep windows closed during pollen season and use central air conditioning with a HEPA filter attachment. This applies to your home and to any vehicle (car, bus, train, etc.).
  • Start taking allergy medicine before pollen season begins. Most allergy medicines work best when taken this way. This allows the medicine to prevent your body from releasing histamine and other chemicals that cause your symptoms.
  • Bathe and shampoo your hair daily before going to bed. This will remove pollen from your hair and skin and keep it off your bedding.
  • Wash bedding in hot, soapy water once a week.  
  • Wear sunglasses and a hat. This will help keep pollen out of your eyes and off your hair.
  • Limit close contact with pets that spend a lot of time outdoors.
  • Change and wash clothes worn during outdoor activities.
  • Dry your clothes in a clothes dryer, not on an outdoor line.

What Is the Treatment for Pollen Allergy?

Certain over-the-counter and prescription medicines may help reduce pollen allergy symptoms.

  • Antihistamines come in pill, liquid or nasal spray form. They can relieve sneezing and itching in the nose and eyes. They also reduce a runny nose and, to a lesser extent, nasal stuffiness.
  • Decongestants are available as pills, liquids, nasal sprays or drops. They help shrink the lining of the nasal passages and relieve nasal stuffiness. Use decongestant nose drops and sprays only on the short-term.
  • Nasal corticosteroids are a type of nasal spray. They reduce inflammation in the nose and block allergic reactions. They are the most effective medicine type for allergic rhinitis because they can reduce all symptoms, including nasal congestion. Nasal corticosteroids have few side effects.
  • Leukotriene receptor antagonists block the action of important chemical messengers (other than histamine) that are involved in allergic reactions.
  • Cromolyn sodium is a nasal spray that blocks the release of chemicals that cause allergy symptoms, including histamine and leukotrienes. This medicine has few side effects, but you must take it four times a day.

Many people with pollen allergy do not get complete relief from medications. This means they may be candidates for immunotherapy. Immunotherapy is a long-term treatment that can help prevent or reduce the severity of allergic reactions. It can change the course of allergic disease by modifying the body’s immune response to allergens.

Allergy Shots - Subcutaneous Immunotherapy (SCIT) has been around for more than 100 years and can provide long-lasting symptom relief. SCIT is a series of shots that have progressively larger amounts of allergen. An injection of the allergen goes into the fat under the skin. Over time, allergic symptoms generally improve. Many patients experience complete relief within one to three years of starting SCIT. Many people experience benefits for at least several years after the shots stop.

Sublingual Immunotherapy involves placing a tablet containing the allergen under the tongue for 1 to 2 minutes and then swallowing it. In 2014, the FDA approved three types of under-the-tongue tablets to treat grass and ragweed allergies. More are in development. You take SLIT tablets daily before and during grass or ragweed season. This treatment offers people with these allergies a potential alternative to allergy shots.

Discuss your allergy symptoms and your allergy treatment plan with your health care provider.


Medical Review October 2015.