Friction blisters as a manifestation of pathomimia.

Self-inflicted skin lesions (pathomimia, artefacts) can be produced in a variety of ways, by the help of nails, razor blades, cigarettes, chemicals, etc. The present study reports three cases of pathomimia, in which the lesions consisted of vesicles or bullae producted by friction. Friction blisters can easily be produced in sites where the epidermis is both thick and firmly attached to the underlying tissues. The blisters have a characteristic histological appearance, which makes it possible to distinguish them from the blisters of different forms of vesicular and bullous diseases and from burn blisters which may also occur in pathomimia.