Some individuals, especially those with lighter skin, are sensitive to the sun. However, about one in a million individuals with a rare genetic condition called xeroderma pigmentosum (XP) suffer from an extreme form of sun sensitivity. Like albinism, XP puts individuals at a high risk of developing skin cancer.¹ Sun protection is important for everyone, but for individuals with XP, it can be life-saving.

If you’ve read our post about photoaging, you’ll know that when you expose your skin to the sun, skin cell DNA absorbs the UV radiation, which causes structural changes to the genetic information. This can cause genetic mutations if our cells are unable to repair the damage. Unfortunately, this is the case for individuals with XP; they are unable to repair the DNA damage due to a genetic deficiency, and this can lead to skin cancer.¹

Individuals with XP should use all available methods of sun protection to avoid the negative consequences of UV exposure. This includes applying and reapplying sunscreen, wearing UV-protective clothing, hats, and UV-protective sunglasses, and seeking shade whenever possible. Individuals with XP even need to be careful indoors, as fluorescent lights can emit UV radiation, and UV rays passing through regular glass windows can pose a risk as well.² On top of using regular sun protection, individuals with XP should regularly see a medical professional for skin exams.³

Since it is unsafe for individuals with XP to spend time in the sun, they are unable to produce vitamin D via sun exposure. For this reason, it is recommended that they take vitamin D supplements to avoid developing a nutritional deficiency.³ The Sun Index team is working on calculating natural vitamin D intake, so stay tuned!

  1. Genetics Home Reference. (2017). Xeroderma Pigmentosum. Retrieved April 3, 2017
  2. MedlinePlus. (2015). Xeroderma Pigmentosum. Retrieved April 3, 2017
  3. Kraemer, K. H. and DiGiovanna, J. J. (2016). Xeroderma Pigmentosum, GeneReviews® [Internet]. Retrieved April 3, 2017