A plasma treatment device (10) comprises a body portion (11) which houses a battery (22), a gas cylinder (15), an power supply circuit (21) and a plasma generator (20) comprising a pair of electrodes (18, 19). The device also comprises a detachable applicator portion (12) and an elongate duct (14) extending from the generator (20) for conveying the generated plasma to an outlet at the distal end of the duct (14) and for directing a plasma plume formed at the outlet onto a treatment area. An annular electrode (25) is disposed at the outlet of the duct (14) and is connected to the power supply circuit (21) via an elongate electrical conductor (26). The annular electrode (25) acts to conduct electrons in the generated plasma away from the emerging plasma plume, so as to help avoid any sensation caused by the resultant current flow. A circuit (17) may be provided for measuring the current flow from the electrode (25), the power supply circuit (21) being arranged for adjusting the power supplied to the pair of electrodes (18, 19) in dependence upon the measured current.
