The job of immune system cells is to find foreign substances such as viruses and bacteria and get rid of them. Normally, this response protects us from dangerous diseases. People with allergies have specially-sensitive immune systems that react when they contact certain harmless substances called allergens. When people who are allergic to ragweed pollen inhale its allergens from air, the common hay fever symptoms develop.
Seventeen species or types of ragweed grow in North America. Ragweed also belongs to a larger family called Compositae. Other members of the family that spread pollen by wind can cause symptoms. They include sage, burweed marsh elder and rabbit brush, mugworts, groundsel bush and eupatorium. Some family members spread their pollen by insects rather than wind, and cause few allergic reactions. But sniffing these plants can cause symptoms.
Who Gets Ragweed Allergy?
Of Americans who are allergic to pollen-producing plants, 75 percent are allergic to ragweed. People with allergies to one type of pollen tend to develop allergies to other pollens as well.
People with ragweed allergy may also get symptoms when they eat cantaloupe and banana. Chamomile tea, sunflower seeds and honey containing pollen from Compositae family members occasionally cause severe reactions, including shock.
What Are Its
reaction to all plants that produce pollen is commonly known as hay fever.
Symptoms include eye irritation, runny nose, stuffy nose, puffy eyes, sneezing,
and inflamed, itchy nose and throat. For those with severe allergies, asthma
attacks, chronic sinusitis, headaches and impaired sleep are symptoms.
How Is It
To identify an
allergy to ragweed or one of its relatives, requires a careful medical history,
a physical exam and testing. The main approach to confirm a suspected allergy
is the skin sensitivity test.
For this, the skin
is scratched or pricked with extract of ragweed pollen. In sensitive people,
the site will turn red, swollen and itchy. Sometimes blood tests are used to
see if an antibody to ragweed is present. This is sometimes necessary, but it
takes longer for processing by a laboratory and it is more expensive.
What Can I Do About
There is no cure
for ragweed allergy. The best control is to avoid contact with the pollen. This
is difficult given the amount of ragweed pollen in the air during pollination
time. There is help, though.
How Ragweed Causes Allergies Like all allergies, ragweed allergy occurs when the body’s immune system mounts a vigorous response to a foreign substance that is actually harmless -- in this case, tiny grains of pollen released by maturing ragweed flowers.
“Your immune system reacts to them as if they were a threat,” says Nathanael S. Horne, MD, clinical assistant professor of medicine at New York Medical College in Valhalla and an allergy specialist in private practice in New York City.
Specialized immune cells start churning out antibodies to proteins in the pollen. The ensuing cascade of biochemical reactions floods the bloodstream with histamine, a compound that causes all-too-familiar allergy symptoms.
Continue reading below... In addition to sneezing, sniffling, nasal congestion, and sleep disruption, ragweed allergy can cause red, puffy eyes, itchy throat, and even hives. Severe cases can lead to chronic sinus problems (sinusitis) and even asthma attacks.