Infrared skin temperature measurement cannot be used to detect myofascial tender spots

Objective: To determine the relationship between skin temperature and press ure tolerance in patients with myofascial pain. Design: Blinded, criterion standard. Setting: Community physiatry clinic. Patients: Sixteen consecutive female patients with myofascial pain or fibro myalgia with shoulder girdle symptoms above the T4 level for at least 3 mon ths. No patient met the exclusion criteria of recent trauma to the area or therapy within 48 hours. Interventions: Skin temperature was measured by using a hand-held infrared thermometer over 36 points arranged in a grid on the upper and midtrapezius . Pressure threshold was then assessed at each point by using a pressure th reshold meter. A second, blinded examiner then examined each patient to fin d any myofascial tender spots and noted within which square on the grid the y occurred. Main Outcome Measures: The correlation between temperature and pressure thr eshold and the temperature differences between tender and nontender areas. Results: A nonsignificant correlation of .023 (p =.57) was found between te mperature and pressure threshold. The mean temperature of the tender spots was 32.1 degreesC. No significant difference existed between tender spot te mperature and temperature of nontender points (32.1 degreesC, p =.653) or c ontralateral points (32 degreesC, p=.893). Conclusions: Skin temperature, measured with a hand-held infrared thermomet er, cannot be used to diagnose and follow treatment progress of myofascial tender spots, because skin temperature over tender spots does not correlate with pressure sensitivity.