Development of terminal hair following skin lesion treatments with an intense pulsed light source.

Laser and other light sources have been used to treat vascular and pigmented skin lesions and to remove tattoos and unwanted hair, with varying degrees of success and various side effects. It has not yet been reported that hair growth can occur as a side effect of such treatments. In this paper two cases are presented, one port wine stain and one tattoo, that were each treated several times with an intense pulsed light source (IPLS) for removal. Terminal hair, not present before treatment, partially developed in treated areas of both lesions. Local inflammatory reactions are believed to trigger such outcomes.