Lyme borreliosis--a review and present situation in Japan.

The skin diseases Erythema (chronicum) migrans (ECM, EM), Lymphadenosis benigna cutis (LABC), and Acrodermatitis chronica atrophicans (ACA) have long been described in northern Europe, and dermatologists are very familiar with these manifestations, which have been successfully treated with penicillin for about 40 years without the causative agent being known. Certain neurologic symptoms could be linked to tickbites during the 1920's and later also to EM. In 1977, Steere et al. reported a new form of inflammatory arthritis, mainly in school children in the community of Lyme, Connecticut, U.S.A., which they could also associate with preceding erythema and tickbites. Five years later, Burgdorfer was able to isolate Borrelia spirochetes from Ixodes ticks, which are known to be vectors of Lyme disease as well as of EM and ACA. The following year, Borrelia spirochetes were also isolated from Ixodes ticks and from skin lesions of patients in Sweden and Germany. These findings resulted in a large number of reports of new discoveries related to this infection, which is now known under the names of tick-borne or Lyme borreliosis and, in the U.S., also as Lyme disease or Lyme arthritis. It has proven to be a great imitator disease, mainly through its involvement of the neurological system, and to be far more widespread than previously thought. The full course of the disease is not yet known, however it is clinically, like another spirochetosis, syphilis, divided into early and late stages. Manifestations involve mainly the skin, the joints, the nervous system (Neuroborreliosis), and the heart. Antibiotic treatment is effective, especially in the early stages. Like syphilis, the disease can be self-healing without treatment. People who are exposed to ticks should be aware of the risk of contracting this disease, also in Japan where Ixodes ticks have been shown to be carriers of Borrelia spirochetes. Cases, particularly of EM, but also with neurological symptoms, have already been diagnosed in Hokkaido, Honshu, Shikoku, and Kyushu. As Lyme borreliosis is now proven to exist in Japan, it is beneficial for dermatologists to know about the various presentations of this disease. This paper will briefly summarize the historical background, the clinical stages, the diagnosis, and the treatment of Lyme borreliosis, with a summary of the present situation in Japan.