Photographs of CPIP rat hind paw and CRPS patients' feet. Comparative photographs of a normal (a), 5 min post-IR hyperemic (c), 24 h post-IR (e), contralateral skinned (g), and 48 hrs post-IR ipsilateral skinned (h) rat hind paw; and normal (b), hot-phase CRPS-I (d), cold-phase CRPS-I (f) foot. Rats are anesthetized in a, c, g and h. Note the similarity between the hyperemic, edematous hot-phase CRPS-I foot and the 5 min post-IR hyperemic hind paw which is also edematous. The 24 h post-IR hind paw appears dry and shinny like the cold-phase CRPS-I foot. The 48 h post-IR ipsilateral skinned hind paw clearly is less well perfused than the contralateral skinned hind paw, comparable to the cyanotic appearance of the cold-phase CRPS-I foot. Human CRPS-I foot photos reprinted with permission from the website of the Reflex Sympathetic Dystrophy Syndrome Association of America. Rat hind paw photos in a, c & e reprinted from Coderre et al., Pain 112, 94–105 (2004) with permission from IASP.