Treatment of gunpowder traumatic tattoo by Q-switched Nd:YAG laser:: An unusual adverse effect

BACKGROUND. The Q-switched Nd:YAG laser can completely eliminate traumatic tattoos, OBJECTIVE. We report the results of the unsuccessful removal of traumatic tattoos among three patients with dermal inclusions of gunpowder who were shot at close range, METHODS. Treatment was tried in each patient with a Q-switched Nd:YAG laser at a medium fluence (4-6 J/cm(2)) RESULTS. During treatment of our patients, each pulse provoked sparks and the immediate formation of bleeding transepidermal pits, After the healing process was completed, we observed poxlike scars and the spreading of pigments in the skin around the initial points of the tattoo. CONCLUSION. We hypothesize that the rapid transfer of high-energy pulses to powder particles creates microexplosions of these fragments resulting in cavitation acid provoking transepidermal holes and subsequent scars. This adverse effect was only produced if the tattoo resulted from gun powder being shoe at a short distance from the skin.