Comparative treatment of multiple vellus hair cysts with the 2940 nm Er:YAG and 1540 nm Er:Glass laser.

Eruptive vellus hair cysts occur sporadically, hereditarily or in association with other diseases due to developmental anomalies of vellus hair follicles. Here, we report on a 41-year-old male with multiple vellus hair cysts of the forehead, who was successfully treated three times with a non-ablative, non-fractional 1540 nm Er:Glass laser on one side of his face, and with an ablative non-fractional 2940 nm Er:YAG laser on the other side, at intervals of 6-12 weeks. Over the whole treatment period of about 9 months, we could observe a marked reduction in the total number of cysts. The bigger and painful inflammatory cysts were reduced significantly. There was a slight tendency for better clinical outcome in the area in which the Er:YAG laser had been used. Clinical and histopathological findings, pathogenesis and treatment options are discussed with a review of the literature.