Button or disc batteries have become increasingly popular as the energy source for electronic devices such as cameras, calculators, computers, watches, hearing aids and children's toys. Button battery burns to the gastrointestinal tract, ear and nose have been reported in children from many centres. Cutaneous injury from these sources has not been similarly reported. We believe our case represents the first, reported to date, to have suffered this injury and highlights this further potential hazard of the small, benign-looking button batteries.