**13.2.5 Reflex sympathetic dystrophy**

Reflex sympathetic dystrophy has also been described elsewhere in this chapter. The typical findings on three-phase bone scan are hyperemia on the first two phases with intense periarticular activity in the affected extremity. In children, a cold variant has been reported, which is characterized by decreased activity in the three phases of the scintigraphy in the affected limb, compared with the nonaffected limb (Shammas, 2009; as cited in Nadel, 2007).
