A skin pricking device includes a housing having an opening formed in a proximal end thereof a spring mounted lancet including a needle within a casing having body and cap parts, interconnected by a separable coupling. The cap part has a cap projecting through the opening allow a user to grip and remove the cap. The device further includes a trigger for firing the lancet. Turning the cap part moves the entire lancet, engaging a trigger stop surface on the distal body part of the lancet with a trigger catch and further biasing the trigger to block the lancet. Further turning of the cap part over a second angle relative to the housing causes the cap part to move in a proximal direction by a further, second distance, thereby axially separating the cap part from the body part, whereby the cap part can then be removed from the device.