Stability of temperature asymmetries in reflex sympathetic dystrophy over time and changes in pain.

OBJECTIVE

To determine the clinical usefulness of skin temperature patterns for tracking reflex sympathetic dystrophy (RSD) by assessing (a) long-term relationships between changes in pain due to RSD and patterns of near surface blood flow and (b) relationships between site of pain and site of greatest asymmetries in near surface blood flow patterns.

DESIGN

Multiple videothermographic evaluations of near surface blood flow patterns were performed on subjects diagnosed as having RSD. At each session, subjects filled in an outline of the body to show the location, intensity, and description of their pain. The thermograms were evaluated independently by two raters for location and intensity of pain, as well as location and degree of temperature asymmetries.

SETTING

Two Army Medical Centers.

SUBJECTS

Thirteen male and 16 female subjects were subsequently diagnosed as having RSD.

OUTCOME MEASURES

Ratings of pain and videothermograms of the lower limbs were used as outcome measures.

RESULTS

All but one subject were usually cooler on the most painful side by at least 0.5 degrees C. The amount of relative coolness was not proportional to pain intensity. There were no consistent overlaps between exact location of pain and greatest thermal asymmetry. Seven subjects were thermally symmetrical on at least one recording. Six subjects were warmer on the affected side on at least one recording. One subject was always warmer on the affected side.

CONCLUSIONS

Videothermography is not an appropriate tool to use alone for either single session diagnosis or multi-session tracking of RSD.