Sufferers' Symptoms
When someone is allergic to ragweed, the immune system treats the plant's pollen as a foreign invader. First, white blood cells produce IgE antibodies that specifically target ragweed pollen. These antibodies attach themselves to mast cells, which exist in large numbers in the nose, eyes, lungs and digestive tract. When pollen is inhaled, these mast cells release histamine and other chemicals that cause the misery of hay fever: sneezing, an itchy, runny nose, and itchy, red eyes. Such symptoms can lead to fatigue, trouble concentrating, and missed days of work or school.
Compared with certain year-round allergens, such as dog and cat dander, seasonal allergens like ragweed may be less likely to cause asthma symptoms. "Animal allergens, for example, are very small, which means they can get deep in the airway and trigger asthma," Randolph explains. "Pollens don't get much below the windpipe, so they cause nasal symptoms."
Still, worsening nasal allergies can generate asthma attacks and can be an important element in asthma treatment.
Some people with ragweed allergies may notice that they develop itchiness around their mouth and in their throat when they eat melons and bananas. This is due to a protein in these fresh fruits that is similar to the one in ragweed. Luckily, this cannot lead to a life-threatening allergic reaction known as anaphylaxis.
While symptoms are often used to diagnose ragweed allergy in the primary care doctor's office, a more accurate approach is a skin sensitivity test performed by a board-certified allergist. In these tests, the skin is pricked with an extract of ragweed pollen. If a person has a ragweed allergy, the skin will become red and swollen.