A 28-year-old patient comes to the office for evaluation of a rash. At first there was only one large patch, but then more lesions erupted suddenly on the back and torso; the lesions itch. On physical examination, you note that the pattern of eruption is like a Christmas tree and that there are a variety of erythematous papules and macules on the cleavage lines of the back. Based on this description, what is the most likely diagnosis?

Question

Quizplus · Accepted Answer

This is a classic description of pityriasis rosea. The description of a large single or "herald" patch preceding the eruption is a good way to distinguish this rash from other conditions.

A 28-Year-Old Patient Comes to the Office for Evaluation of a Rash