The Skin Cancer Foundation covers this:
[A]fter the sunburn fades, lasting damage remains.
Sunburn accelerates skin aging and is a leading cause in the majority of cases of basal cell carcinoma, squamous cell carcinoma and melanoma, the deadliest form of skin cancer.
The later went on to say:
- Skin damage builds up over time starting with your very first sunburn. The more you burn, the greater your risk of skin cancer. Subsequent UV damage can occur even when there is no obvious burn.
- Five or more sunburns more than doubles your risk of developing potentially deadly melanoma
Cancer Research UK says similar.
The Centers for Disease Control and Prevention (CDC) points out:
Any change in skin color after UV exposure (whether it is a tan or a burn) is a sign of injury, not health. Over time, too much exposure to UV rays can cause skin cancers including melanoma (the deadliest type of skin cancer), basal cell carcinoma, and squamous cell carcinoma. UV exposure can also cause cataracts and cancers of the eye (ocular melanoma). Every time you tan, you increase your risk of getting skin cancer.
More can be read in Chapter 3 of the CDC Traveller's Health Yellow Book 2020 (Free access via the CDC) which lists the following references:
American Cancer Society (n.d.). Skin cancer. https://www.cancer.org/cancer/skin-cancer.html
Diaz, J. H., & Nesbitt Jr, L. T. (2013). Sun exposure behavior and protection: recommendations for travelers. Journal of travel medicine, 20(2), 108-118. https://doi.org/10.1111/j.1708-8305.2012.00667.x
Monteiro, A. F., Rato, M., & Martins, C. (2016). Drug-induced photosensitivity: Photoallergic and phototoxic reactions. Clinics in dermatology, 34(5), 571-581. https://doi.org/10.1016/j.clindermatol.2016.05.006
Skin Cancer Foundations (n.d.). Sun protection. https://www.skincancer.org/skin-cancer-prevention/sun-protection/
Young, A. R., Claveau, J., & Rossi, A. B. (2017). Ultraviolet radiation and the skin: Photobiology and sunscreen photoprotection. Journal of the American Academy of Dermatology, 76(3), S100-S109. https://doi.org/10.1016/j.jaad.2016.09.038