The skin can be sensitive to the sun for a variety of reasons: it is underdeveloped (childhood), or inflamed (atopic dermatitis or acne), or due to photosensitivity induced by drugs or dermatological treatments. In these cases it is vital to use protection with a Sun Protection Factor (SPF) suitable for each type of skin.
Sensitivity to the harmful effects of ultraviolet radiation is inheritable. Numerous large-scale studies have identified genetic variations that enhance sensitivity to the sun and the tendency we have to suffer from sunburn (erythema).
The genes related to skin pigmentation (ASIP, TYR, MC1R, and OCA2) and a low tanning capability are those that most influence the skin’s sensitivity to the sun. In addition, there is a strong association between DNA repair genes and the tendency to suffer from sunburn. These genes have no relation to tendency to tan, so there is an underlying mechanism to burns that is independent of pigmentation.