Infection by spirochete Borrelia burgdorferi is mainly observed in the United States where it has taken the name of Lyme's disease, and in Europe. Its evolution may be very extended, in several phases. A few weeks after a tick-bite, the primary lesion appears, which is a chronic migrating erythema. In the following weeks or months, in the secondary phase, nerve lesions may appear, quite similar in Europe and in the United States, and cardiac lesions, mostly seen in the United States. In the following weeks, months, or years, during the tertiary phase, articular lesions may appear, frequent in the United States, much more unusual in Europe. Several years later, chronic lesions of the central nervous system may appear, described in the United States, and chronic skin lesions such as chronic atrophying acrodermatitis sometimes associated with destructive lesions of the joints underlying the skin lesion, which are only recognized in Europe. The discovery of the spirochete in a small number of these lesions, including the latest in the evolution, permits to think that, throughout this evolution, this disease is secondary to the persistence of the germ within the body; this explains the efficacy of the penicillin treatment, including in the oldest forms of the disease. Serology is quite reliable; but it becomes positive only 2 to 4 weeks after the onset of the chronic migrating erythema: needless to say the importance of this single cutaneous lesion which enables to make the diagnosis and requires the use of a tetracycline or penicillin treatment.
疏螺旋体伯氏疏螺旋体感染主要见于美国（该病在当地被称为莱姆病）和欧洲。其病程可能很长，分为几个阶段。蜱叮咬后几周，会出现原发性损害，即慢性游走性红斑。在接下来的几周或几个月的第二阶段，可能会出现神经损害，在欧洲和美国表现颇为相似，还可能出现心脏损害，这在美国更为常见。在接下来的几周、几个月或几年的第三阶段，可能会出现关节损害，在美国较为常见，在欧洲则更为罕见。几年后，可能会出现美国所描述的中枢神经系统慢性损害，以及慢性皮肤损害，如慢性萎缩性肢端皮炎，有时还伴有皮肤损害下方关节的破坏性病变，这种情况仅在欧洲被认识到。在少数这些损害中发现了螺旋体，包括病程后期的损害，这使人认为，在整个病程中，该病是由病原体在体内持续存在所致；这就解释了青霉素治疗的有效性，包括对该病最陈旧形式的治疗。血清学检查相当可靠；但在慢性游走性红斑出现后2至4周才会呈阳性：不用说，这种单一的皮肤损害对于诊断至关重要，并且需要使用四环素或青霉素进行治疗。
