A massage head including a casing forming an internal chamber defined by a back wall, two lateral walls, and two transverse walls, and open on its surface opposite to the back wall, and having a skinfold formed therein when the head is applied to a patient's skin. The head is formed of two modules provided with means capable of enabling to reversibly fasten them to each other. Each of the modules integrates a functional element defining one of the transverse walls of the internal chamber.