A 69-year-old man with suspected Lyme disease visited an infectious disease specialist in the outpatient clinic. 3 weeks earlier, he felt a painful bite in his left buttock, caused by a tick that was later removed. After several days, significant weakness, drowsiness, chills and muscle pains occurred, followed by a 2 cm red inflammatory infiltration appearing in the location of the bite with crust over the ulceration and enlarged left inguinal lymph nodes (Figure 1 A).