An Unusual Summer Tan

August 5, 2015

A summer tan failed to conceal this embarrassing rash on an 18 y/o boy’s arms, back, and chest. Can you make a diagnosis?

An 18-year-old boy presents with a hypopigmented scaly macular rash appearing predominately on his back, chest, and arms. The rash became more apparent as he acquired his “usual summer tan.” He reports no other skin problems.

What is the most likely diagnosis?