Make the Diagnosis: Strange Rash Surfaces

(MedPage Today) — Case Findings: A 20-year-old man went to the doctor complaining of a fever. He had been hiking recently with friends and had gotten a significant number of insect bites, which he had been scratching non-stop – particularly one on his hand, which had become quite red. An erythematous rash in a linear configuration had spread up his arm. Upon exam, the doctor noted regional lymphadenopathy.

Can you diagnose the patient?
Source: Dermatology