The Gorlin Syndrome Alliance asked Dr. Jean Tang, Professor of Dermatology at Stanford University, some frequently asked questions about sunscreen.
What is the difference between sunscreen and sun block? They are the same.
What qualities should we look for in sunscreen / block for children? Broad spectrum sunscreens using physical blockers (zinc oxide or titanium oxide) are the best for children.
What is the safest type of sunscreen / block that children should use? Physical blocker sunscreens (those with titanium dioxide and zinc oxide) are the safest for children because the chemical blockers may pass through the skin and enter the blood stream in children with thin skin.
At what age is it safe to change to sunscreen that older individuals / adults may use? During the teen years, it becomes safe to use sunscreens with physical and chemical blockers.
What qualities should we look for in sunscreen / block for adults? Adults can use the physical and chemical blockers (the chemical ones provide a wider UVA and UVB coverage).
What is the safest type of sunscreen / block that adults should use? I don’t recommend a particular brand – because there are so many ingredients and personal tolerance of different brands. I always like to say that the safest type is the ONE you will use regularly and doesn’t cause problems (rash, dryness, too smelly for you etc.).
What is the difference between physical and chemical blockers in sunscreen? Chemical sunscreen absorbs into the skin and then absorbs UV rays, converts the rays into heat, and releases them from the body. Physical sunblock sits on top of the skin and reflects the sun’s rays. The minerals titanium dioxide and zinc oxide are the main active ingredients in physical blocks.
Are there any components of sunscreens that should be avoided completely? The benzophenones, cinnamates, and dibenzoylmethanes may induce photo-allergic reactions. Avoid things you may have allergies to – some patients have allergies to chemical sunscreens with ingredients such as Oxybenzone (benzophenone-3), the most widely used UVA blocking agent. This is the most common cause of sunscreen-induced photo-allergic contact dermatitis
Some put on sunscreen after brushing their teeth in the morning. How often should sunscreen be re-applied after that throughout the day? If you go in water or sweat, then re-apply after 3-4 hours.
What is the ideal sunscreen in the following three scenarios? In these we understand the desire to protect our skin and live a fulfilling life within the constraints of GS.
- Regular but short intervals of sun throughout the day (e.g. school). Avoid peak sunlight hours like 11am to 3pm. Wear a wide brimmed hat (don’t just focus on sunscreen) and a long sleeve shirt – these items do a much better job than sunscreen. Put on sunscreen in AM.
- Limited sun exposure (indoor camps, sick days, travel in plane). Travel in plane is ok, avoid long outdoor activities. Put on sunscreen in AM.
- Extensive sun exposure (beach day, water or amusement park, canoe trip, outdoor sports tournament). Put on sunscreen in AM and re-apply if you are sweating it off (after 3-4 hours). Rely more on hats and long sleeves.