An apparatus adapted to inhibit pain signals generated by pain receptors in the skin during a skin related medical treatment such as an injection. An evacuation chamber is provided with an essentially rigid interface element larger than a threshold surface area through which a medical treatment can be administered to a selected skin region, one or more walls which are placeable in the vicinity of the skin region, an interior defined by the walls and by the interface element, and an opening at the bottom of the interior which is sealable by the skin region. A device generates a vacuum within the evacuation chamber interior to a level greater than the threshold vacuum level suitable for drawing the skin region through the opening towards, and in a compressing relation against, the interface element, to inhibit the transmission of a pain signal generated by pain receptors located within the skin region.