A 28-year-old man presented for evaluation of a new-onset rash on his back. The patient noted mild pruritus and a burning sensation. He denied any additional symptoms. His past medical history was insignificant, and he was not taking any current medications. The rash began 3 days following the return from a hunting trip in central California, during which he wore the same shirt for 3 days consecutively. Figure 1 shows when the rash was first recognized, displaying clusters of well-demarcated, smooth, erythematous papules and plaques along the midline of his back. The rash continued to grow at a surprising rate, and he eventually developed overlying weeping vesicles. Six days after onset, additional linear lesions were noted on the lower extremities that were not evident during the initial presentation (Figure 2).
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