Does this lesion indicate cellulitis or Lyme disease?

A European traveller guesses at the right diagnosis, helping him on the road to recovery

Jerome, an otherwise-well 60-year-old man, presents with a red patch on his left thigh.

He takes olmesartan for hypertension and has no other significant medical history, medications or known drug allergies.

He lives in a rural town in the east of France and arrived in Australia five days before presentation.

The lesion was first noticed the day after arrival. On examination, Jerome appears well.