Should you put sunscreen on children every day or just days when they’ll be outside for a long time or the sun is extra bright? And, what level of sunscreen should you use?
DR. BLUM’S RESPONSE
Sunscreen: how often it should be applied and what type depends on who you ask. Most dermatologists would recommend wearing sunscreen whenever going outside. Dermatologists would say that even average, daily, incidental sun exposure can cause problems such as early aging of skin and wrinkles, and increase the number of moles a person develops, which could potentially lead to skin cancer. If you ask someone who has an interest in Vitamin D as an important nutrient, they would tell you that sun exposure in small amounts can be very healthy because it increases Vitamin D production.
As in most things, I think that the truth is always in between. Most people say that they feel very good when they get some sun exposure and I would agree with that. We need to listen to our bodies and do what feels good sometimes. That said, my belief is that a small amount of daily sun exposure is healthy and unlikely to lead to problems. Ten to 20 minutes of daily exposure, without sunscreen, will produce a good amount of Vitamin D and is likely to be safe.
If a person is going to out in the sun for a long time, sunscreen is essential. The SPF number is important to understand and will help you choose which type to use in different situations. For someone with medium toned skin it takes about 20 minutes of sun exposure to develop a sunburn. For people with darker pigment, say of Indian or African descent, it will take longer to get burned but it will still happen. For a very fair skinned person, for example someone red haired from Ireland, it will take less than 20 minutes.
The SPF is Sun Protectant Factor and it is the denominator of a formula that predicts time until burning. Basically you can multiply 20 minutes by the number of the SPF and find out how many minutes it takes to get burned. For example, SPF 30 would take 30 times the 20 minutes or 600 minutes. This is 10 hours of direct sun exposure to develop a sunburn with an SPF of 30. An SPF of 50 would last 1000 minutes, or nearly 16 hours. Swimming will reduce the time of protection so if swimming the sunscreen should be re-applied every few hours.
As you can see an SPF of 30, or even 15, is good enough for most situations. The cost tends to increase as the SPF number increases and there is usually no need to spend the extra money because the protection of the lower numbers will still last longer than most people stay in the sun.
Dr. Robert M. Blum is a pediatrician at Southfield Pediatrics in Bingham Farms and West Bloomfield. Email him questions at firstname.lastname@example.org.