The invention concerns a body-mountable device, in particular a patch for a medical assembly (14), comprising a housing portion (16) adapted to receive the medical assembly (14) and having a bottom side (32), and further comprising a fastening means (18) which is connected to the housing portion (16) and adapted to affix the housing portion (16) to the body (20) of a patient, such that the bottom side (32) is facing the body (20), wherein a fluid-guiding component (22) is configured on the bottom side (32) of the housing portion (16) for guiding a fluid emanating from the body (20) to the periphery of the housing portion (16).
