Which sun-related factor is a known risk factor for melanoma when occurring in youth?

• A. Regular sunscreen use
• B. Three or more blistering sunburns before age 20
• C. Wearing protective clothing
• D. Avoiding sun altogether

Answer: (B)

Severe UV exposure in youth drives DNA damage in skin cells, and blistering sunburns are a sign of intense damage. Having three or more blistering sunburns before age 20 markedly increases melanoma risk later because the early mutational load in melanocytes rises with repeated high-dose UV exposure. Protective behaviors—regular sunscreen use, wearing protective clothing, and avoiding sun when possible—reduce UV exposure and lower risk, rather than increase it. Therefore, the factor described as three or more blistering sunburns before age 20 is the known youth melanoma risk factor.