Sunburned for Science

Barely two months after extolling the benefits of sunscreen, I have a sunburn. Do as I say, not as I do. In light of this sunburn, I’ll be interrupting my planned next post on alcohol to look into effective sunburn treatments.

Sunburn pain is more thoroughly researched than I expected because it’s used as a method for inducing pain in studies on anesthetics. The other common method for inducing pain, by the way, is to stick needles into people’s jaws. My thanks go out to the brave souls who volunteered to be sunburned and stuck with needles.

Goo-ocaine

This RCT says a 10% benzocaine cream was effective at reducing pain but not itchiness from a sunburn. The goo I bought off Amazon has 0.5% lidocaine, so my immediate question was whether lidocaine is as effective is benzocaine. This RCT and this RCT say 2% lidocaine, 5% lidocaine, and 20% benzocaine are all equally effective at reducing pain from a needle. Although these studies are all small and short, they seem to be well controlled and in this case the short term is all we care about. The full-texts for all three papers aren’t available for free, so I can’t say much else about them.

Ibuprofen

This RCT found mixed results. Ibuprofen was not effective on the day of sunburn, but was effective at a follow up visit. We could try to make sense of this, but it might just be random. In contrast, this RCT found that 800 mg of ibuprofen was very effective at reducing pain the day after a sunburn. This RCT also finds mostly null results for ibuprofen, except for reddening of the skin. This review also finds that ibuprofen doesn’t do anything for sunburn other than mildly reducing skin redness.

Hydrocortisone Cream

This RCT found no “clinically relevant” benefit to hydrocortisone cream. This RCT did find clinically relevant benefit to hydrocortisone cream. I find no meta-studies to settle the dispute.

Aloe

I struggled to find any rigorous studies of aloe. I’ve found websites that refer to “research” that they never specify and reputable sounding websites that support the use of aloe with no explanation, but I haven’t found research that supports its use.

This review says, “not much convincing information is available on properties of the gel.” They find one study of the antioxidant properties of aloe in sunburned rats, but that’s about 1,000 miles away from whether aloe effectively reduces sunburn pain in humans. This RCT finds that aloe has, “no efficacy in sunburn treatment when compared to placebo.” Livestrong also claims there’s essentially no scientific evidence about aloe’s effect on sunburns. This blog post has some more colorful commentary on and paper links about the use(lessness) of aloe vera. There doesn’t seem to be any strong reason either to use or to avoid aloe vera gel for sunburn.

American Academy of Dermatology

Oddly, the American Academy of Dermatology recommends the use of aloe and discourages the use of the goo-ocaine’s, exactly the opposite conclusion I came to here. They provide no citations and no explanation. Obviously don’t take my uneducated blog post as medical advice, but I’m skeptical of how the AAD came to this conclusion. On the same webpage they recommend that you “ask your parents about taking ibuprofen,” so I wonder if their advice was written by an intern who was just spouting conventional wisdom instead of stating the official recommendations of the AAD.

Sunburns of the Future

I wouldn’t expect any cutting edge research on treatments for sunburn pain. And yet, here it is in PNAS. See the story in Smithsonian Magazine here. Maybe in the not-too-distant future there will be new and better treatments for sunburn pain.

Glossary

Words I had to look up to understand these papers:

Erythema – reddening of the skin caused by increased blood flow in superficial capillaries.

Hyperalgesia – increased sensitivity to pain

Pruritus – itch