Clinical Considerations in Sunscreen Use

Sunscreens are being prescribed and used very extensively today. From understanding how sunscreens protect against solar light, the focus is now on how sunscreens impact human health and the environment. This chapter deals with the practical considerations around using a sunscreen and helps the dermatologist to make informed ingredient choices, and to advise patients on the best sunscreen for a specific background, such as for sensitive skin or for those with a connective tissue disorder. The relationship between sunscreen use and vitamin D deficiency and sunscreen use and hair loss as frontal fibrosing alopecia (FFA) have been explored in detail, in addition to segments dealing with best sunscreen practices for special categories like pregnancy, nursing mothers, and children. Application parameters such as sunscreen durability, need for reapplication, and the quantities of sunscreen application for optimal protection have been discussed from a user point of view, enabling clinicians to effectively answer questions faced when counselling patients on sunscreen use. Specifically, the need for a 2 hourly reapplication of sunscreens has been reexamined in the light of new data demonstrating the sustained performance of sunscreens even up to 8 h, when performing regular or increased physical activity, indoors or outdoors.