Reflex sympathetic dystrophy (RSD or causalgia) has been rarely reported in children. We now report a 10-year-old boy with RSD in whom we performed extensive ancillary investigations including thermography, bone scintigraphy and dermo-echography. The clinical, laboratory and ancillary studies reported here highlight the profound focal acquired autonomic disturbance in this disorder. The patient presented a compression of the deep peroneal nerve at the inferior extensor retinaculum in the affected limb. Surgical decompression lead to rapid improvement of the patient's condition. Peripheral nerve decompression should be considered as a possible treatment of RSD in children, particularly those that are refractory to conservative maneuvers.