[Immunohistochemistry of Borrelia type spirochetes].

We have looked for the presence of Borrelias by immunohistochemistry in cutaneous biopsies taken from patients with positive Borrelia serology. We used the monoclonal antibody "P41 Borrelia burgdorferi flagellin". We found Borrelias in the dermis of Pick-Herxheimer disease (3/3), erythema chronicum migrans (6/9), lymphocytoma (1/3), and morpheas (2/5). They were also seen in the vascular wall of hypodermal arterioles in a case of cutaneous periarteritis nodosa (1/2). Treponema pallidum was not revealed by the antibody.