Abstract: A laser treatment head in which an elongate applicator is shaped to access a bodily cavity. At the distal end of the applicator is a deflector protected by a window. At a proximal end of the applicator is a drive that can axially displace and rotate the applicator in a helical pattern such that laser beam pulses deflected to the mucosa area applied along a helical path to the wall of the cavity. The drive comprises a stationary hollow shaft inside a rotatable sleeve. The shaft has a helical channel in its outer surface and the sleeve has a longitudinal slot through its wall. A pin attached to the proximal end of the applicator extends through the slot and into the channel. When the sleeve is rotated, the slot advances the pin along the channel, moving the attached applicator in the helical pattern.