The usage of radio frequency (RF) as a nonablative approach to treating aged and pho – todamaged skin has been growing in popularity since its introduction in the mid-1990s. The technique is based on the mechanistic principle that the elevation of temperature inside the dermal layers leads to a transient structural denaturation of collagen fibrils, followed by contraction and tightening of the skin upon cooling. The net effect observed by the patient is an overall firming of the skin, including reduction in fine lines and wrinkles. It should be noted that a temperature elevation to at least 42° C should also elicit a heat shock response from dermal fibroblasts. This is of particular relevance for an impact upon fine lines and wrinkles, since it has been reported that heat shock treatment of dermal fibroblasts elicits a net increase in collagen production. Thus, it cannot be ruled out that the newly synthesized collagen also plays a mechanistic role in the benefits observed from RF treatment.
The level of efficacy attained via RF is relatively modest [59] but measurable changes can occur with as few as two treatments over a one-month period [60]. In addition, there do not appear to be many significant negative side effects [61]. Not surprisingly, this further supports the view that there appears to be a direct correlation with nonablative devices between lowered efficacy and reduced negative side effects.