Introduction: Lichtenberg figures are reddish, fern-like patterns that appear on the skin when a patient is struck by lightning. These appear to be a result of an inflammatory response as current spreads out causing ionisation and heat effects and damage to the small subcutaneous capillaries.
Case report: A 30-year-old lady was brought to the accident and emergency department with a history of momentary loss of consciousness. All that the patient could recollect was that she had been on the phone when she heard a loud bang following which she 'blacked out'. On examination, she had characteristic cutaneous Lichtenberg figures. These revealed the true diagnosis of a lightning strike conducted through the phone line into the patient.
Discussion: The cutaneous manifestation of a surreptitious lightning strike through a telephone plays an important role in diagnosing the problem and is particularly significant when the patient is unconscious and unable to give a history of events or, as in this case, has retrograde amnesia. Establishing the diagnosis enables us to look for other lightning-associated injuries and to monitor the cardiac status of the patient to avoid any concomitant complications. Also, establishing the diagnosis is extremely helpful to allay patient anxiety as Lichtenberg figures on the skin can be quite dramatic, as seen in this case.