Echinacea Linked to Allergies
WebMD News Archive
Jan. 22, 2002 -- Echinacea was recently found to be one of the top 10 most popular herbs and supplements. But a new study shows that this herb shouldn't be taken lightly as it can cause life-threatening allergic reactions.
Echinacea is commonly taken to help prevent colds and other infections. But as with other supplements, the dangers of echinacea are somewhat a mystery.
Two allergy specialists in Australia were asked to see five people after each one had an apparent reaction to echinacea. The study appears in the January issue of Annals of Allergy, Asthma, and Immunology.
After taking echinacea, two of the five people developed a severe, life-threatening reaction called anaphylaxis. When this occurs, breathing is difficult due to swelling in the airways, and blood pressure can fall to deadly levels.
A third person had a sudden asthma attack 10 minutes after their first-ever dose of echinacea. The fourth person had multiple mild asthma attacks each time echinacea was taken. And the last person had a rash within two days of taking the herb, which came back when the echinacea was taken again.
Each person had skin testing for allergies to echinacea, and three of the five had a reaction.
The researchers' findings raise an interesting point. The only way to develop an allergic reaction to a substance is to have been exposed to it before. But in this case, at least one of the people had never taken echinacea before.
The researchers suggest that you can become sensitized to have an allergy to echinacea by coming in contact with other plants in the environment, such as grass or tree pollens. They also point out that people with other allergies are more likely to have a reaction to echinacea.
This would be consistent with a prior study that showed one in five people with allergies had a positive skin allergy test to echinacea -- even though most had not taken it before.
The researchers then looked to see how many other echinacea allergies had been reported in Australia. They found 51 other cases of possible echinacea allergy. They again found some serious reactions, including four who were hospitalized.