The invention relates to a nozzle for a device for the dermo-cosmetic treatment of brown skin spots by means of cyto-selective cryotherapy, comprising a spray nozzle supplied from a reservoir of high-pressure liquefied cryogenic gas, characterised in that the application nozzle comprises an upper ring (11) to be connected to a shell (8) and extending into a central body (12), the side wall (12a) of which narrows towards the bottom, includes longitudinal openings (10) and defines a gas expansion chamber that is in communication with a frustoconical dispersal channel (13a) which is located inside an end piece (13) to be applied to the skin and which opens out through a discharge port (13b).
