A topical isolation module includes a gas impermeable shell 1 having a wall 1a and defining a substantially closed internal chamber. The wall has an opening that communicates with the internal chamber, and the chamber being arranged to cover an external portion of a user's body to be treated. Sealing means 5 provided along the perimeter of the opening, which are arranged to seal the shell to the user's body about the portion to be treated. Gas introduction means, which are arranged to introduce one or more therapeutic gases, such as oxygen or carbon dioxide, into the substantially closed internal chamber. There is also a light source arranged to irradiate the portion to be treated. The light source may be LEDs emitting light of wavelength 390 nm, 630 nm, or 980 nm. The pressure in the chamber may be controlled by a control unit, and there may be a pressure relief valve.
