Shade from a beach umbrella alone does not provide enough protection from extended exposure to ultraviolet (UV) rays, indicating that a combination approach with an umbrella and sunscreen may be needed to optimize protection, a study published in JAMA Dermatology has shown.1
Sun-protective behavior impacts skin cancer prevention. Although shade, which works by physically shielding skin, protects against direct harmful UV rays, reflected and indirect UV rays may still reach the skin.
Because there is insufficient clinical evidence that a beach umbrella alone can provide adequate skin protection, researchers sought to directly measure sunburn protection conferred by a standard beach umbrella compared with that offered by sunscreen with a high sun protection factor under actual use conditions.
For the single-center, evaluator-blinded, clinical study, researchers enrolled 81 people with Fitzpatrick skin types I (1%), II (52%), and III (47%) in Lake Lewisville, a lake in north Texas 159 meters above sea level. Participants were randomly assigned to use a beach umbrella alone or only sunscreen with a sun protection factor of 1 while sitting on a sunny beach for 3.5 hours at midday.
Investigators then evaluated each participant for clinical sunburn on all exposed body sites 22 to 24 hours after sun exposure, including the face, back of the neck, upper chest, arms, and legs.
Results showed that participants in the umbrella only group had a statistically significant increase in clinical sunburn scores compared with baseline and had higher postexposure global scores vs the sunscreen alone group (P <.001).
Investigators observed a total of 142 sunburn incidences in the umbrella group compared with only 17 in the sunscreen group. In addition, 78% of the 41 participants assigned to use the umbrella had erythemia in 1 or more sites vs 25% of the 40 participants in the sunscreen group (P <.001).
However, researchers found that neither the umbrella nor the sunscreen alone completely protected beachgoers from sunburn, suggesting that a combination approach may be necessary.
These findings can help clinicians to educate their patients, particularly those with a history of skin cancer and those on medications associated with photosensitivity, on the most effective strategies to prevent sunburn.
1. Ou-Yang H, Jiang LI, Meyer K, et al. Sun protection by beach umbrella vs sunscreen with a high sun protection factor. JAMA Dermatol. 2017 Jan 18. doi: 10.1001/jamadermatol.2016.4922. [Epub ahead of print]