Echinacea no cure-all for kids.

Children suffer an average of 6-8 upper respiratory infections (URIs) each year, each lasting 7-9 days. Decongestants and cough suppressants often provide little relief for children under 12, prompting many parents to try alternatives such as the popular herbal remedy echinacea (Echinacea spp.). But a study published 3 December 2003 in JAMA suggests echinacea is no better than a placebo at limiting the duration or severity of cold symptoms, and in some cases may cause a rash.

A team led by pediatrics professor James Taylor of the University of Washington analyzed data on 707 URIs in 407 children aged 2-11. Echinacea was used to treat 337 of the URIs, and placebo was used for 370. Parents administered the treatment from the start of the cold until all symptoms had resolved, up to 10 days. They also kept a log of their children's symptoms.

The double-blind study showed the herbal remedy failed to affect the duration or severity of cold symptoms in the children. A mild rash appeared in 7.1% of the treated children, compared with 2.7% of the placebo group. Taylor cautions against giving the herb to allergy-prone youngsters.

His results mirror those of a Wisconsin study published 17 December 2002 in the Annals af Internal Medicine, which showed echinacea did not relieve cold symptoms in adults. Yet several European researchers have reported echinacea does bring relief. Taylor speculates they might have used a higher dose, a different part of the plant, even a different species (Taylor's group used dried E. purpurea, from the aboveground plant, in an alcohol-free liquid).

Proponents of alternative medicine offer another explanation. "Echinacea may have more of a role in preventing than treating," says Leanna Standish, a senior research scientist at Washington's Bastyr University and a member of Taylor's research team. Indeed, among children in Taylor's placebo group, 64.4% developed more than one cold during the four-month study, compared with 52.3% of the echinacea group.

To fully understand how herbal remedies work, researchers must isolate the active ingredients. "We need better information on what it takes to make echinacea active," says Diane Birt, director of the NIEHS Center for Research on Dietary Botanical Supplements at Iowa State University. "We need to define the right stuff."