Water immersion-induced skin wrinkling test in complex regional pain syndrome.

An 11-year-old boy was referred for right leg pain that had lasted for 3 months. No history of trauma was documented, and infectious, vascular, and neoplastic evaluation was unremarkable. Physical examination revealed atrophy of the right lower limb, and the right foot was cold and pale. He demonstrated allodynia with light tactile stimulation. He also complained of decreased heat and cold sensation and decreased sweating of the affected limb. A water immersion-induced skin wrinkling test was performed. Compared with the left toes, decreased skin wrinkling of the right toes was observed after immersion in warmwater (104.0 F) for 20 minutes (Fig 1). Thermal tomography of the right lower limb showed a lower surface temperature (Fig 2). In the absence of vascular disorder, the result suggested peripheral sympathetic dysfunction of the affected limb. A diagnosis of complex regional pain syndromewas made. Trigger point injection provided some relief for the pain, and physical therapy was commenced.