TNF and complex regional pain syndrome: Increased IL-6, MCP-1 and macrophage inflammatory protein 1β (MIP-1β) were also found in the blister fluid from the affected limb.25 Although classic inflammation seems more relevant to the warm phase of CRPS, some studies have suggested that even in the cold stage inflammation may play a role, as well.26 For instance, it has been shown that the levels of pro-inflammatory cytokines IL-6 and TNFα in the affected extremity are comparably disturbed between cold and warm CRPS.