History: Lyme borreliosis is a complex, multisystemic disorder caued by infection with the spirochete Borrelia burgdorferi. The most striking signs and symptoms involve the joints, central and peripheral nervous systems, heart and skin. Ixodes (I.) ticks are the primary vectors and disease occurs in areas where these ticks are endemic. I. scapularis (dammini) is the major vector in the eastern US and I.pacificus is the vector in the westen part of the US. I.ricinus is the major vector in Europe. At early stage of disease erythema chronicum migrans (ECM), which a diagnostic manifestation, is present in up to 75% of patients. Classic ECM starts as an erythematous papule at the bite site and then evolves into an annular, erythematous ring. There are few symptoms associated with ECM, although some patients complain of mild pruritus or tenderness. ECM clears spontaneously within weeks or months in most cases. The diagnosis may be suspected and confirmed by the characteristic eruption, ECM, which occurs in 50-70% of patients. At this stage the diagnosis is primairly based on clinical grounds since the serologic test may not become positive for a number of weeks. This case a 52-year old female with the chief complaint of annular ECM, without a history of tick bite. Meanwhile the patient is under doxycline therapy and will be recalled back for serological testing in 4 weeks time.