A needle device comprising a housing which can be mounted to an injection device (1). The housing comprises a first housing element (13) provided towards a proximal end of said needle device (6) and a second housing element (15) provided towards a distal end of said needle device (6). A cutting element (14) is arranged at said first housing element (13). A cannula having a blunt proximal end (11) is fitted to the second housing element (15). The first housing element (13) and the second housing (15) element are moveable relative to each other between an extended position where the proximal end of the cannula (11) does not extend beyond the proximal end of the cutting element (14) and a compressed position wherein the cannula (11) extends past the proximal end of the cutting element (14). This construction greatly reduces the risk of post-treatment bruising and tissue trauma.