Allergies to pollen are prevalent in the midsummer and early fall. Nearly all such allergies are due to ragweed. Ragweed, a member of Ambrosia species, grows floridly in summer climates. Goldenrod is another flowering plant that produces large amounts of pollen. While goldenrod is frequently blamed for allergies due to its bright, conspicuous flowers, it almost never causes allergies. The allergic syndrome of ragweed is termed "hay fever." Hay fever is treated by avoiding pollen and with antihistamine medications.
Causes
The function of the immune system to eradicate foreign invaders such as bacteria, viruses and fungi. Allergies are caused by an abnormal reaction of the immune system to a harmless substance. According to the National Institute of Environmental Health Sciences, ragweed season is worst between August and November, with peak season in mid-September. Each grain of pollen is carried by winds that can carry it up to 400 miles from the plant.
Goldenrod, a plant commonly mistaken for the allergy-producing plant, has a bright yellow color. It also blooms toward the late summer. The pollen of goldenrod is heavy and sticky and is thus less liable to be carried by wind currents.
Symptoms
Ragweed allergy has a variety of symptoms. Common complaints include a runny and itchy nose, itchy throat, sneezing and watery, puffy eyes. Swollen, blue-colored skin below the eyes, also known as "allergic shiners," may be seen. Some may have asthma attacks, chronic headaches and difficulty sleeping. Though the manifestations of hay fever are uncomfortable, they are rarely dangerous.
Diagnosis
The diagnosis of ragweed allergy is straightforward. Usually a physician can make the diagnosis with a careful history and physical examination. A blood test may show a high levels of eosinophils, cells which are implicated in the allergic response. A definitive test can be made by a skin test. In this test, small amounts of different allergens are injected into the skin to look for an allergic reaction. If a person is allergic to a given substance, he will develop redness and swelling at the site of injection.
Treatment and Prevention
The most important part of prevention is to avoid the causative pollen. This can be done by staying indoors in an air-conditioned environment as much as possible during ragweed season. The worst times of the day are in the mornings between 5 a.m to 10 a.m. A variety of medications are useful for hay fever. According MayoClinic.com, first-line treatments are antihistamines, such as fexofenadine, loratidine and cetrizine. Other treatments are nasal steroids, decongestants, montelukast and cromolyn sodium. Immunotherapy, in the form of allergy shots, can be used in resistant cases.
