Recurrent erythema nodosum associated with echinacea herbal therapy

We report a case of recurrent erythema nodosum that is temporally and perha ps causally associated with use of echinacea herbal therapy. The genus Echi nacea is traditionally used as an immunostimulant in the prophylaxis and tr eatment of upper respiratory tract infections. In vitro and in vivo studies of echinacea administration in animal anti human-derived models suggest a definite stimulatory effect un the cellular immune system, although the cli nical impact of echinacea is still unknown. The public's increasing use of alternative and complementary therapies necessitates that dermatologists be familiar with the cutaneous adverse effects of these agents.