Bracelet Burn--An Unusual Electric Burn--Benjamin K. Fisher and Israel Dvoretzky BRACELET BURN--AN UNUSUAL ELECTRIC BURN

A car mechanic sustained a deep partial thickness burn of the wrist when his metal watch strap short circuited the battery of a car upon which he was working. CASE REPORT A twenty-eight year old car mechanic was seen in the skin clinic of the Chaim Sheba Medical Centre on January 30th, 1975 with a burn of the left wrist sustained four days previously. He had been handling the engine of a vehicle which had two 12 volt batteries connected in series (i.e. a 24 volt unit) and two supporting iron rods connecting the back of the engine frame to its front. Inadvertently the patient's stainless steel watch strap touched both the positive pole of one battery and the adjacent iron rod causing a short circuit through the watch strap (Fig. 1). The patient experienced pain but was unable to pull away his hand for several seconds until the heat generated caused melting of the watch strap which broke and freed his hand. The patient immediately noticed a linear bracelet-like black burn involving the strap area of the watch but sparing the area under the watch itself. The burn seemed worse on the sides of the wrist than on the volar aspect where the metal clip was located. Fig. 1. Car battery, short-circuited through patient's stainless-steel watch-strap, which touched battery's pole and a supporting iron rod above it. Patient demonstrates accident