Preventing solar damage
Ultraviolet (UV) radiation (UVA and UVB) causes sunburn, photoageing, cataracts, immunosuppression and skin cancer. UV radiation can also activate latent viruses and trigger photosensitivity-related dermatoses. Visible light and infrared radiation also contribute to photodamage and skin cancer.
Advise patients to minimise solar damage to the skin by following the SunSmart advice1:
- slip on clothing
- slop on sunscreen
- slap on a hat
- seek shade
- slide on sunglasses.
Educational tools and handouts for patients are available from the SunSmart website.
The active ingredients in sunscreen either absorb or reflect UV radiation. Absorbent sunscreen chemicals act mainly in the UV range. Reflectants (also called physical blockers) act across the whole solar radiation spectrum, including visible light. Broad-spectrum sunscreens usually contain a physical blocker (eg titanium dioxide, zinc oxide) plus a UVB- and UVA-absorbing agent. A review by the Therapeutic Goods Administration in 2017 concluded that, based on current evidence, titanium dioxide and zinc oxide nanoparticles in sunscreens were not likely to cause harm when sunscreens are used as directedTherapeutic Goods Administration (TGA), 2017.
Sun protection factor (SPF) is a laboratory-derived ratio indicating the ability of a sunscreen to block UVB from the skin. When used as directed, SPF 30 sunscreen filters 96.7% and SPF 50 filters 98% of UV radiation.
Ensure that patients understand they need to apply a thick layer of sunscreen, and reapply it regularly. For detailed advice on applying sunscreen, see the SunSmart website.