CALCINOSIS CUTIS FOLLOWING CALCIUM-CHLORIDE ELECTRODE PASTE APPLICATION FOR AUDITORY-BRAIN-STEM EVOKED-POTENTIALS RECORDING

Circumscribed calcification in the dermis (calcinosis cutis) has been reported following electroencephalographic and electromyographic studi es at sites of electrode placement following application of an electro de paste containing calcium chloride. Prolonged exposure and skin micr oabrasions seem to increase the risk of this rare complication of elec trode placement, which has not been previously reported following audi tory brainstem evoked potential recordings. We report the appearance o f localized dermal calcifications at the sites of electrode placement (forehead and retroauricular areas) following auditory brainstem evoke d potential recordings in two children, aged 3 and 2 years, respective ly. In both cases the electrodes were applied after gentle scrubbing w ith an ethanol-impregnated gauze and interposition of a calcium chlori de bentonite magma paste. The recording took about 1 hour. Erythematou s macules and plaques ranging from 4 to 12 mm in diameter, studded wit h small stony excrescences, appeared at the areas of electrode applica tion I and 5 days later, respectively. Histopathologic study of 4 mm p unch biopsy specimens showed amorphous dermal deposits of calcium salt s. There was superficial ulceration and transepidermal elimination of the calcium deposits, as well as a foreign body tissue reaction in the surrounding dermis. In both patients small stony pellets were extrude d during the healing process, which took 11 and 9 weeks, respectively, and left no scars.