Thermal and mechanical sensory testing. Patients with complex regional pain syndrome (CRPS) had mechanical hyperalgesia to skin fold testing (A) and to joint pressure (B) on the affected hand (CRPS) compared with the contralateral pain-free hand (pain-free) and on the pain-free hand compared with controls. They had thermal hyperalgesia to cold pain in glabrous (C) and hairy skin (D) and to heat pain in glabrous (E) and hairy skin (F) on the affected hand (CRPS) compared with the contralateral pain-free hand (pain-free) and on the pain-free hand compared with controls. Control 1 = the hands in the controls matching the pain-free hand in the patients; control 2 = the hands in the controls matching the CRPS hand in the patients. Significant changes are indicated by asterisks.