Effect of different methods of thermotherapy on skin microcirculation

Objective: The purpose of the study was to compare the effects of different methods of thermotherapy on skin microcirculation, skin temperature, and core temperature in patients with rheumatoid arthritis and in healthy persons. Design: In 20 patients with rheumatoid arthritis and 20 healthy controls, the skin microcirculation was measured by means of laser-Doppler flowmetry before, at the end of, and 30 mins after completion of local thermotherapy (infrared light, paraffin, peat) in the lumbar area. In addition, skin and core temperature were recorded at the same point in time. The influence of previous intake of acetylsalicylic acid on skin microcirculation during thermotherapy was investigated. The controlled trial was conducted in an air-conditioned laboratory. Results: All methods caused a significant increase in skin microcirculation (flow and vasomotion), skin temperature, and core temperature. The skin temperature showed the highest increase when infrared light was applied. The microcirculation became more intense when paraffin fango was used. There were no differences between the reactions of rheumatoid arthritis patients and healthy persons. The additional intake of 500 mg acetylsalicylic acid before treatment did not affect skin temperature or skin microcirculation. A tendency toward a sinusoidal rhythmization of vasomotion was detected. Conclusions: The effects of the three methods of thermotherapy differ quantitatively due to their physical attributes. The effects on circulation differ depending on the method chosen, and this is significant when selecting the least stressful method for a particular patient. Rheumatoid arthritis patients and healthy controls have the same increase of skin microcirculation in the lumbar area. Findings in the distal limbs might differ. All used therapies cause a rhythmization of the vasomotion and, as a consequence, a qualitative improvement of the microcirculation.