Echinacea, adverse reaction

Other components in the Echinacea products may contribute to many of the adverse reactions reported, not only Australian, but also the United States, United Kingdom, Canada and New Zealand. Additional studies are needed to further support the IgE-mediated hypersensitivity reported in Echinacea-containing products. Studies could include growing and processing of Echinacea under environmentally controlled conditions, with the intent to minimize foreign contaminants, and administration of extracts to patients under supervision. Although this would not represent real-world conditions, it may further support or refute the IgE-mediated hypersensitivity observed in subjects taking commercial Echinacea products. Additional work is also needed to identify the component responsible for the IgE-mediated hypersensitivity. 

Mullins, R. and Heddle, R. 2002. Adverse reactions associated with Echinacea, the Australian experience. Ann. Allergy Asthma Immun. 88, 42—51. 

The basis for this anaphylactic reaction was hypersensitivity to Echinacea, confirmed by skin prick and RAST testing. However, others have challenged the notion of a causal relation in this case (28). Nevertheless, the author affirmed his belief that Echinacea was the causal agent and reported that at that time Echinacea accounted for 22 of 266 suspected adverse reactions to complementary medicines reported to the Australian Adverse Drug Reaction Advisory Committee (28). 

Mullins RJ, Heddle R. Adverse reactions associated with echinacea the Austrahan experience. Aim Allergy Asthma Immunol 2002 88(1) 42-51. 

A retrospective analysis of aU adverse events related to herbal medicines and dietary supplements reported to the California Poison Control System has given data on the risks of the adverse effects of herbal medicines (112). Between January 1997 and June 1998, 918 calls relating to such supplements were received. Exposures resulting in adverse reactions occurred most often at recommended doses. There were 233 adverse events, of which 29% occurred in children. The products most frequently implicated were zinc (38%), Echinacea (8%), witch hazel (6%), and chromium picolinate (6%). Most of the adverse events were not severe and required no treatment hospitalization was required in only three cases. 

Morris, C.A. and Avom, J. 2003. Internet marketing of herbal products. JAMA 290, 1505-1509. Moulds, R. and Malani, J. 2003. Kava Herbal panacea or liver poison Med. J. Aust. 178, 451-453. Mullins, R. and Heddle, R. 2002. Adverse reactions associated with Echinacea The Australian experience. Ann. Allergy Asthma Immunol. 88, 42-51. 

Bielory, L. 2002. Adverse reactions to complementary and alternative medicine Ragweed s cousin, the coneflower (echinacea), is a problem more than a sneeze. Ann. Aller. Asthma Immunol 88, 7-9. Bleasel, N., Tate, B., and Rademaker, M. 2002. Allergic contact dermatitis following exposure to essential oils. Aust. J. Dermatol. 43, 211-213. 

The Australian Adverse Drug Reaction Advisory Committee received 11 reports of adverse reactions associated with echinacea use between July 1996 and September 1997. There were three reports of hepatitis, three of asthma, one of rash, myalgia, and nausea, one of utricaria and one of anaphylaxis. There are other published reports of echinacea associated with contact dermatitis and anaphylaxis. ... 

Echinacea has been generally well tolerated in clinical trials, with most trials reporting similar incidences of adverse reactions for Echinacea and placebo (Huntley et al. 2005). One trial of fresh juice of Echinacea purpurea aerial parts in children showed a significantly higher incidence of rashes in children taking the Echinacea preparation than in children taking placebo (Taylor et al. 2003). 

Flu-like symptoms (eg, fever, shivering, headache, vomiting) have been reported following the intravenous use of Echinacea extracts. Adverse effects with oral commercial formulations are minimal and most often include unpleasant taste, gastrointestinal upset, or central nervous system effects (eg, headache, dizziness). Allergic reactions such as rash, acute asthma, and anaphylaxis have been infrequently reported. 

Five cases of adverse drug reactions have been attributed to oral Echinacea extracts (26). Two of the patients had anaphylaxis and one had an acute attack of asthma. The authors also tested 100 atopic subjects and found that 20 of them, who had never before taken Echinacea, had positive reactions to skin prick tests. 

In Germany from 1989 to 1995, there were 13 adverse events possibly associated with the use of Echinacin (pressed juice from E. purpurea herb). Only four of these, all allergic skin reactions, were thought to be related to use of the product. During this time period, several million people were thought to treat themselves or obtain a prescription for an Echinacea product (9). 

Allergic reactions to Echinacea products have been reported see Adverse Events and Side Effects, below). Some authorities have suggested that the reactions may be due to the presence of Echinacea poUen in products, as allergies to pollens in the Asteraceae family are common. Ingestion of products made from the flowering top of Echinacea are thus more likely to result in allergic reactions than products made from the root and leaf (Mills and Bone 2005 Upton and Graff 2004). 

In clinical trials and reviews of clinical trials. Echinacea products have been noted as being well tolerated, with adverse events reported similar to those of placebo (Huntley etal. 2005). Allergic reactions to Echinacea species have been reported (Coeugniet and Elek 1987 George et al. 2006 Huntley et al. 2005 Kemp and Franco 2002 Lee and Werth 2004 Logan and Ahmed 2003 Moell 1951 Mullins 1998 Mullins and Heddle 2002 RSseler 1952 Soon and Crawford 2001). 

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