Figure 1 A 54-year-old man was struck by lightning and was initially stuporous. The emergency medical team found him conscious and in sinus rhythm, with normal vital signs and numbness and paresthesia of the left shoulder, flank, and leg. On his arrival at the emergency department, he felt well, and an examination revealed a fern-leaf pattern of erythematous, painless cutaneous marks on his left arm, back, buttocks, and left thigh. The electrocardiogram was normal, and the serum concentrations of creatine kinase and myoglobin were slightly elevated. The patient was sent home after 24 hours. On a follow-up visit two days later, he had no traces of the fern-leaf pattern of marks.