Ragweed Allergy

Ragweed allergy refers to an adverse immune system reaction to ragweed plants. Ragweed is a type of weed that grows predominantly in the eastern and midwestern United States in the early fall months (August through November). When ragweed blooms, it produces pollen, a yellow, powdery substance that fertilizes other plants. Pollen counts, which measure the amount of airborne pollen in the area, are usually highest in the morning. Although most ragweed pollen falls near its plant of origin, ragweed pollen can travel up to 400 miles away. 

A ragweed allergy occurs when an individual’s immune system is sensitive to ragweed pollen. An allergic reaction, or allergy, is the body’s natural response to exposure to an allergen, or foreign substance. An individual may touch, inhale, or ingest an allergen. More rarely, exposure to an allergen may occur via injection. When an allergen, like ragweed pollen, enters the body of an individual who is sensitive to that substance, the immune system activates, and inflammatory chemicals, such as histamine, are released to help fight off the invader. These inflammatory chemicals can cause the characteristic symptoms of seasonal allergies (e.g., congestion, sneezing, runny nose). 

Predisposition to a ragweed allergy can be hereditary. If any family members are allergic to ragweed or other pollen, an individual is more likely to develop a specific allergy to ragweed.

Ragweed allergy symptoms can include sneezing, mucus congestion in the throat and nose, and a runny nose. Individuals also commonly experience itchiness in the eyes, nose, and throat. 

Individuals allergic to ragweed might also have symptoms of oral allergy syndrome, or OAS. With OAS, the immune system can confuse ragweed pollen with certain foods, like watermelon, zucchini, cantaloupe, bananas, cucumbers, and honeydew. When these foods are eaten, the immune system will react and mount an immune response, which may result in itching or swelling of the mouth, throat, or face.

There is currently no cure for a ragweed allergy; however, there are treatments that can help manage the symptoms. 

Preventive measures may be an option. An individual can limit exposure to sources of ragweed pollen by keeping all windows closed in both homes and cars, washing their hands after touching animals that have been outdoors, removing shoes and changing clothes after coming indoors, and showering before going to bed. Some individuals may also benefit from using a saline nasal spray, which can help flush allergens and mucus from the nasal cavity. 

Certain over-the-counter (OTC) medications are often recommended by healthcare professionals to help alleviate symptoms. A few commonly-recommended OTC antihistamines are loratadine (Claritin), fexofenadine (Allegra), and cetirizine (Zyrtec). Nasal steroid sprays, like fluticasone (Flonase), can alleviate inflammation in the nose and help reduce nasal congestion. It can be beneficial to start taking these medications before the onset of symptoms, especially before pollen counts rise during the peak of ragweed season. 

If over-the-counter medications do not provide enough symptom relief, or if symptoms persist for long periods of time, a prescription oral steroid, like prednisone, can be helpful. For persistent itchiness of the eyes, steroid eye drops, such as loteprednol (Alrex), may be prescribed. 

Over-the-counter decongestants, such as oxymetazoline (Afrin) or pseudoephedrine (Sudafed), can shrink swollen nasal passageways and may provide some relief, but they should be used only as directed, as they can be dangerous for individuals who have high blood pressure or heart problems. In addition, decongestant nasal sprays can make symptoms worse if used longer than a few days.