Ultraviolet radiation and the skin: Photobiology and sunscreen photoprotection

J Am Acad Dermatol. 2017 Mar;76(3S1):S100-S109. doi: 10.1016/j.jaad.2016.09.038. Epub 2016 Dec 27.


The efficacy of sunscreens can be measured by different methods, involving in vitro, ex vivo, or in vivo techniques. There is a need for a worldwide standardization of these methods to avoid misunderstanding and confusion among sunscreen users. The clinical benefits of sunscreens have been demonstrated in randomized controlled trials that established the role of sunscreens in the prevention of actinic keratoses, squamous cell carcinomas, nevi, and melanomas. Sunscreens also prevent photoimmunosuppression and signs of photoaging. Continued efforts in public education on the proper application of sunscreens and the practice of photoprotection in general are needed.

Keywords: DNA photodamage; cyclobutane pyrimidine dimer; photoaging; photoimmunosuppression; pyrimidine(6-4)pyrimidone; skin cancer; sunscreen; ultraviolet radiation.

MeSH terms

  • DNA Damage / radiation effects
  • Health Education
  • Humans
  • Immune Tolerance / radiation effects
  • Radiation Protection / methods*
  • Skin Aging / radiation effects
  • Skin Diseases / prevention & control
  • Skin Neoplasms / prevention & control
  • Skin Pigmentation
  • Sunburn / prevention & control
  • Sunlight / adverse effects*
  • Sunscreening Agents / standards
  • Sunscreening Agents / therapeutic use*
  • Ultraviolet Rays / adverse effects*


  • Sunscreening Agents