A 19-year-old previously healthy woman presented with a 3-day history of red-purple papules on her feet that started after a day of walking on the boardwalk at the beach in hot weather. She initially noticed these lesions around the outline of her flip-flop sandals. She also reported some mild aching in her feet but denied other associated symptoms. She was not taking any medications. Physical examination was significant for purpuric papules on her feet, sparing the straps of her sandals (Figure 1). Laboratory tests, including a complete blood cell count, a comprehensive metabolic panel, and assays for antinuclear antibody, rheumatoid factor, hepatitis B, hepatitis C, complement levels, and C-reactive protein, were unremarkable. Punch biopsies were performed, and specimens were submitted for histopathologic examination (Figure 2 and Figure 3) and direct immunofluorescence