Have you got many scars? When I have needed medical treatment after hours (I usually wait til I can see my own GP) I just say that I have a cut that I need looked at; show them, and then all my other scars are exposed. The staff ask questions but I just say that I will contact my nurse the next day, that I am safe, and if I need help I will pick up the phone. This usually reassures them enough.
(((((griffe))))) good luck.