Primers and Assay-IDs of the TaqMan assays used.

<p><b>Abbreviations:</b></p><p>IL: interleukin; TNF: tumor necrosis factor-alpha.</p

Boxplots show the intraepidermal nerve fiber density (IENFD) in affected versus unaffected skin of patients with postherpetic neuralgia (PHN).

<p>In affected skin IENFD is lower than in corresponding (contralateral) unaffected skin (*p<0.05). The horizontal black line in the box marks the median value.</p

Characteristics of CRPS patients and control subjects.

*<p>unpaired t-test</p>#<p>Yates-corrected chi-square</p

Thermal pain thresholds in acute and chronic CRPS.

<p>Cold pain thresholds (A) and heat pain thresholds (B) are significantly lowered in acute CRPS (corresponding to cold and heat hyperalgesia). Pain partially (cold pain) or totally (heat pain) recovers to normal in chronic CRPS. Significant increases of similar magnitude are also found in the contralateral “unaffected” hand for heat pain (B) and to a lesser extent in cold pain (A). Significance vs. controls: *** p<0.001; Significance vs. acute CRPS: ⁺⁺⁺ p<0.001; Significance vs. ipsilateral hand: ^(§) p<0.10, ^§ p<0.05. Note: Significance marks that bridge symbols of ipsilateral and contralateral hands apply to both hands. Error bars show 1SEM.</p

Thermal detection in acute and chronic CRPS.

<p>Cold Detection Threshold</p><p>WDT: Warm Detection Threshold</p><p>TSL: Thermal Sensory Limen</p

Standardised comparison of QST data normalised to mean and standard deviation of the control group (z-normalisation).

<p>Normalised data show a severe sensory loss in acute CRPS for all thermal detection parameters (CDT, WDT, TSL) in the affected ipsilateral hand (>1 SD of controls), but also a moderate loss in the contralateral hand, which aggravates in chronic CRPS. In contrast, there is a substantial gain in thermal nociception (CPT, HPT) in acute CRPS (hyperalgesia), equally expressed in both hands (≈1 SD of controls). Heat hyperalgesia almost fully subsides in chronic CRPS, while significant cold hyperalgesia is retained. For the sake of clarity there are no symbols of statistical significance in this figure (c.f. respective paragraph in results).</p

(A) Paradoxical heat sensation (PHS) to mild cold stimuli as elicited by alternating cold and warm stimulation (TSL).

<p>PHS was a frequent finding in both hands in acute CRPS, and fully subsided in the chronic phase. Significance vs. controls: *** p<0.001; Significance vs. acute CRPS: ⁺⁺⁺ p<0.001; Significance vs. ipsilateral hand: ^(§) p<0.10, ^§ p<0.05. Note: Significance marks that bridge symbols of ipsilateral and contralateral hands apply to both hands. (B) PHS-positive CRPS patients (PHS+) exhibited a significantly more pronounced cold hyperalgesia than PHS-negative CRPS patients (PHS−). In contrast, there was no such difference in heat hyperalgesia. Error bars show 1SEM.</p

Thermal nociception in acute and chronic CRPS.

<p>HPT: Heat Pain Thresholds</p><p>CPT: Cold Pain Threshold</p

Proposed modified research diagnostic criteria for CRPS. ^*

*<p>Bruehl S, Harden RN, Galer BS et al. External validation of IASP diagnostic criteria for Complex Regional Pain Syndrome and proposed research diagnostic criteria. International Association for the Study of Pain. Pain 1999; 81: 147–154.</p