Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial.

CONTEXT: Echinacea is a widely used herbal remedy for treatment of upper respiratory tract infections (URIs). However, there are few data on the efficacy and safety of echinacea in treating URIs in children.

OBJECTIVES: To determine if Echinacea purpurea is effective in reducing the duration and/or severity of URI symptoms in children and to assess its safety in this population.

DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind, placebo-controlled trial of healthy children 2 to 11 years old recruited from a regional practice-based network and an alternative medical center in 4-month periods from 2000 through 2002.

INTERVENTIONS: Study patients were randomized to receive either echinacea or placebo for up to 3 URIs over a 4-month period. Study medication was begun at the onset of symptoms and continued throughout the URI, for a maximum of 10 days.

MAIN OUTCOME MEASURES: Primary outcomes were duration and severity of symptoms and adverse events recorded by parents; secondary outcomes included peak severity of symptoms, number of days of peak severity, number of days of fever, and a global assessment of severity of symptoms by parents of study children.

RESULTS: Data were analyzed on 707 URIs that occurred in 407 children, including 337 URIs treated with echinacea and 370 with placebo. There were 79 children who completed their study period without having a URI. The median duration of URIs was 9 days (95% confidence interval, 8-10 days); there was no difference in duration between URIs treated with echinacea or placebo (P =.89). There was also no difference in the overall estimate of severity of URI symptoms between the 2 treatment groups (median, 33 in both groups; P =.69). In addition, there were no statistically significant differences between the 2 groups for peak severity of symptoms (P =.68), number of days of peak symptoms (1.60 in the echinacea group and 1.64 in the placebo group; P =.97), number of days of fever (0.81 in the echinacea group vs 0.64 in the placebo group; P =.09), or parental global assessment of severity of the URI (P =.67). Overall, there was no difference in the rate of adverse events reported in the 2 treatment groups; however, rash occurred during 7.1% of the URIs treated with echinacea and 2.7% of those treated with placebo (P =.008).

CONCLUSIONS: Echinacea purpurea, as dosed in this study, was not effective in treating URI symptoms in patients 2 to 11 years old, and its use was associated with an increased risk of rash.