Derm Dx: Boy with nausea, vomiting and fatigue develops a red, blotchy rash that blanches with pressure

A 5-year-old febrile boy with nausea, vomiting and fatigue develops a red, blotchy rash that blanches with pressure on his wrists, ankles and forearms about a week after returning from a camping trip with his family in the southeastern United States.

Within 24 hours the rash spreads to his palms and soles and then up his arms and thighs to ...