Therapeutic device (1 a, 1 b) to reduce pain and inflammation of bunion inside the shoe, comprising a plate-like body (10), in a flexible and elastically deformable material, formed as a substantially rectangular trapezium, where the minor base is replaced by a concave arc (401) having a given radius of curvature, said body (10) being intended to be coupled to the patients foot by means of a layer (11) of adhesive material, of much lower thickness than the said body (10), connected to the base wall (111), while the top wall (101) is designed for contact with the shoe, being located in use the ends of said device provided with the arch (401) in proximity the joint of the first metatarsal with the big toe, while the square angle of the said body (10) is facing towards the neck of the foot.