OBJECTIVETo observe the impacts of the different distances of moxibustion on local skin temperature and provide a safy distance of moxibustion.

METHODSThree healthy adult volunteers were included. The pure moxa stick (without other herbs mixed together) was used. The moxa-stick moxibustion and the mild moxibustion (with moxa box) were applied to Zusanli (ST 36) on the right side and Guanyuan (CV 4) respectively. The distance from moxibustion to the local skin was 2 cm, 3 cm and 4 cm separately. The moxibustion time was limited by 3 cm stick burned out. The infrared thermography was adopted to record and store thermal images and made the systematic analysis. The same trial was repeated on the second day. The means of the skin temperature measured at each acupoint each time was taken as the results for the analysis.

RESULTS(1) Moxibustion with moxa box at Guanyuan (CV 4): at the distance of 4 cm, the local skin temperature at over 44 degrees C [(44.1 +/- 1.3)-(46.7 +/- 1.5) degrees C)] lasted 7 min; at the distance of 3 cm, the local skin temperature at over 44 degrees C [(44.1 +/- 1.3)-(49.3 +/- 2.0) degrees C] lasted about 10 min and that at over 49 degrees C [(49.0 +/- 2.1)-(49.3 +/- 2.0) degrees C)] lasted 2 min; at the distance of 2 cm, the observation could not be followed due to local burning pain. (2) Moxa-stick moxibustion at Zusanli (ST 36): at the distance of 4 cm, the skin temperature was ranged from (40.0 +/- 2.0) degrees C to (44.9 +/- 2.3) degrees C; at the distance of 3 cm, in 1 min of moxibustion, the skin temperature increased over 44 degrees C, sustaining in the range from (45.9 +/- 3.0) degrees C to (47.8 +/- 2.0) degrees C; at the distance of 2 cm, the observation could not be followed due to local burning pain.

CONCLUSIONIn moxibustion, the closer the moxa stick to the skin is, the higher the local skin temperature is. No matter with stick moxibustion or box moxibustion, the distance of moxa stick to the skin should be in the range from 3 to 4 cm.