The effects of infrared radiation on the human skin.

Background: Infrared radiation (IR) is the portion of the electromagnetic spectrum between visible light (VL) and microwaves, with wavelengths between 700 nm and 1 mm. Humans are mainly exposed to ultraviolet (UV) radiation (UVR) and IR through the sun. Unlike UVR which is well known for its carcinogenic properties, the relationship between IR and skin health has not been as extensively studied; as such, we gather the available published evidence here to better elucidate this relationship.

Methods: Several databases including Pubmed, Google Scholar, and Embase were searched for articles relating to infrared radiation and the skin. Articles were selected for their relevance and novelty.

Results: Detrimental effects such as thermal burns, photocarcinogenesis, and photoaging have been reported, though evidence suggests that these may be due to the thermal effects produced secondary to IR exposure rather than the isolated effect of IR. There are currently no chemical or physical filters specifically available for protection against IR, and existing compounds are not known to have IR-filtering capacity. Interestingly, IR may have some photoprotective properties against the carcinogenic effects of UVR. Furthermore, IR has been used with encouraging results in skin rejuvenation, wound healing, and hair restoration when given at an appropriate therapeutic dose.

Conclusion: A better understanding of the current landscape of research surrounding IR can help illuminate its effects on the skin and highlight areas for further research. Here, we review relevant data on IR to assess its deleterious and beneficial effects on human skin, along with possible means for IR photoprotection.