Giant Ragweed Allergy IgE Blood Test

Order a giant ragweed allergy IgE blood test to detect an allergy to giant ragweed. This test measures the amount of allergen-specific antibodies in a blood sample.

Giant ragweed is one of the most common causes of seasonal allergies in the United States. Individuals who have ragweed allergies are reacting to its pollen and are unlikely to go away once developed. Giant ragweed plants are a tall, hairy, rough summer annual. Some leaves have three lobes, the most common leaf type, while others have five lobes with clusters of female flower heads and elongated clusters of male flower heads towering above. There are at least 17 ragweed species that grow in North America. The plants thrive in grasslands, dry slopes, coastal areas, roadsides, sandy flats, forestry regeneration sites, other disturbed sites, and agricultural fields. 

Giant ragweed plants release a tremendous amount of pollen - generally in the millions of grains. Traveling by air, the pollen grains are released in clumps. The clumps are held together by pollenkitt, a sticky substance. The clumps break apart, allowing the pollen grains to be spread far and wide. 

Ragweed season usually begins in early August and ends in mid-October and is worse when days are warm and dry and nights are cool. Peak ragweed hours are between 10 a.m. and 3 p.m. Counts are lower in the early morning and late afternoon.

An allergy to giant ragweed triggers a reaction in an individual's immune system. The body views certain substances as toxic and produces IgE antibodies to these contaminants. These antibodies cause histamine to be released, which will cause the symptoms of an allergic reaction.

Allergy symptoms vary from one individual to the next ranging from mild to severe reactions, which can be experienced within minutes to hours after exposure. Common symptoms of a giant ragweed allergy may include one or more of the following symptoms:

• Coughing or wheezing
• Itchy, watery eyes
• Sinus pressure causing facial pain
• Scratchy throat
• Swollen, dark-colored skin under the eyes
• Runny nose or congestion
• Poor sleep
• Decreased sense of taste or smell