Long-term, irradiation-induced effects on thermoregulation in the skin after thermal stimulation.

PURPOSE: The morphological effect of radiation on the skin has been adequately analyzed, but the functional effect has received little attention. The purpose of this study was to examine the long-term effects of radiation on the skin from the viewpoint of function.

MATERIALS AND

METHODS

Physiological changes in the irradiated skin of patients who had undergone breast-conserving therapy for the treatment of breast cancer were examined throughout the follow-up period. Thermal stimulation was applied to both breasts, and changes in skin temperature and sweating reactivity of irradiated and non-irradiated skin were measured.

RESULTS

From three weeks to the end of radiotherapy, the resting skin temperature of the irradiated region was significantly elevated, while the rate of sweating was lower. More than two years after radiotherapy, the elevated resting skin temperature of the irradiated region had returned to within the range observed for non-irradiated skin, although an abnormally high increase in skin temperature after thermal stimulation continued to be observed for more than two years after radiotherapy. At the same time, sweating after thermal stimulation continued to be suppressed.

CONCLUSION

Present observations suggest that functional effects, such as the skin temperature and sweating ability of irradiated skin, persist longer than readily visible morphological changes.