A case of cutaneous polyarteritis nodosa improved by drinking bidens pilosa tea as an alternative therapy

A 35-year-old woman presented a 7-year history of indurated painful erythematous lesions on the leg. A histopathological examination revealed necrotizing vasculitis and thrombosis of small muscular arteries in the subcutaneous tissue. Fibrinoid degeneration was observed with infiltration of lymphocytes and histiocytes in and around the vessel wall of the affected artery, which was found to have a clear internal elastic lamina by Elastica van Gieson staining. Laboratory and systemic abnormalities were absent, leading to the diagnosis of cutaneous polyarteritis nodosa. We treated her with an oral non-steroidal anti-inflammatory drug, diaminodiphenyl sulfone, together with vasodilators and prednisolone without any beneficial effects. However, after she started to drink Bidens pilosa (B. pilosa) tea, the skin lesions were much improved without any recurrence. B. pilosa tea is recognized as an effective remedy for livedo vasculopathy. We recently demonstrated that the antioxidant-rich B. pilosa extract decreases reactive oxygen species and increases nitric oxide in human dermal endothelial cells. B. pilosa tea may be a useful adjunct for the treatment of microcoagulopathy in cutaneous polyarteritis nodosa.