17-year-old male with quickly spreading rash

The patient is a 17-year-old male who awoke with intensely itchy scattered vesicles over his arms, face, and legs the day after returning from a camping trip. Additionally, his right eye was edematous and nearly swollen closed.
He reported that over the course of the day, the rash seemed to get worse and spread to more areas on his body.
View the image taken and consider what your diagnosis would be.