Dear Straight Dope: I need help settling whether it’s a good idea to put toothpaste on a minor burn. My wife has been doing this since she was a child and says it helps with the pain and severity of the burn. I’m dubious and worry that some of the substances in the toothpaste could make the burn worse or irritate the skin. I’ve heard cool water is the best treatment, but it doesn’t help much with the pain. I’ve been unable to find a credible source one way or the other, so I turn to you: is toothpaste a safe and effective treatment for minor burns? What is the best home treatment for burns? Please help, my daughter’s future burn care depends on it! Cameron
SDStaff MsRobyn with assistance from Qagdop the Mercotan replies:
Having suffered many minor burns in the kitchen myself, I’m familiar with the cool-water treatment recommended by my Girl Scout first-aid training. I’m not familiar with putting toothpaste on a burn, but there may be something to that idea, which I’ll get to shortly.
The kinds of burns we’re talking about are first degree burns, in which the epidermis – the outermost layer of skin – reddens and swells. Such burns are painful because the nerve endings are damaged. The redness is due to the body’s tendency to dissipate excess heat through the skin; you also see this phenomenon when your skin turns red during a hot shower. The swelling is due to the leakage of fluids into the damaged tissue.
Most minor first-degree burns heal by themselves. In second- and third-degree burns, tissue damage is much more extensive, and these generally require medical attention to reduce the risk of further injury.
When you run cool water over a hot burn, the heat from the burned skin dissipates into the cooler water. If you merely soak the body part in water, they’ll end up being the same temperature, which isn’t especially helpful. Running the tap over the burn will keep the water cool, which means more opportunity to get rid of the burn’s heat. There’s also an anesthetic effect as the cool water partly numbs the damaged nerve endings.
Whatever you do, don’t use ice or snow to cool a burn – freezing the skin will worsen the injury. Animal research has shown that if the water isn’t below freezing but is still too cold, you get more tissue damage than if you didn’t cool it at all. Too cold means between 32 to 46 degrees Fahrenheit (0 and 8 degrees Celsius). Just right is between 54 to 65 degrees Fahrenheit (12 and 18 degrees Celsius).
Duration of cooling time is important too. Ideally the skin should be cooled for at least 20 minutes.
Cooling a burn has benefits beyond what you’d expect from simply lowering the temperature of the tissue. The mechanism isn’t fully understood, but cool temperatures seem to reduce the rate of apoptosis (programmed cell death) after thermal exposure, meaning lots of cells decide not to die because they’ve been cooled off. This means fewer dead cells releasing tissue necrosis factors, cytokines, and other nasty chemicals which further damage the injured tissue.
Some studies indicate the lower temperature also reduces tissue oxygen levels at a time when more oxygen means more oxidation in the damaged cell and thus more cell destruction. Also, hypoxia may encourage the skin to begin the healing process quickly. All these things can often mean that what would have been a nasty 2nd degree burn (and possibly worse) without cooling ends up being a painful but nonetheless readily healed, non-scarring first degree burn.
But you asked about treating burns with toothpaste. In general this is a bad idea. Toothpaste is sticky, and some formulations can be gritty. That means toothpaste can rub injured skin open and because it’s not sterile make it more susceptible to infection. Frankly, the thought of toothpaste on a burn makes me cringe.
However, there’s something to using mint, or at least menthol, on a burn. Noxzema skin cream, which contains camphor, menthol and eucalyptus, was first introduced as a sunburn remedy and is still a reliable standby for that as well as other kinds of skin irritation. Menthol in particular triggers a specific nerve receptor responsible for the sensation of coolness, although it doesn’t actually reduce the temperature of the skin. It also triggers the kappa opioid receptors, which gives menthol its analgesic effect. These products also help keep the burn clean, which is never a bad thing.
As a fair-skinned redhead, I swear by Noxzema and Dr. Bronner’s peppermint soap in the summer because the mint oils keep me from looking like a lobster. (Believe me, the drawn-butter jokes get old fast.) I have no scientific basis for why that is, it just is.
Aloe vera juice also works well. Many people keep a potted aloe plant in their kitchen for that reason, and large leaves are available at some supermarkets. Just break the leaf open and gently rub the juice on the burn.
Of course, the best way to treat a burn is to prevent it entirely. As my home economics teacher (and a lot of experience) taught me, a hot utensil looks exactly the same as a cold utensil. Invest in a good set of oven mitts and nonconducting spoons. Personally, I like Oxo utensils. They’re ergonomic and I don’t get burned when I touch them. Can’t ask for much more than that.
SDStaff MsRobyn with assistance from Qagdop the Mercotan
Send questions to Cecil via firstname.lastname@example.org.
STAFF REPORTS ARE WRITTEN BY THE STRAIGHT DOPE SCIENCE ADVISORY BOARD, CECIL'S ONLINE AUXILIARY. THOUGH THE SDSAB DOES ITS BEST, THESE COLUMNS ARE EDITED BY ED ZOTTI, NOT CECIL, SO ACCURACYWISE YOU'D BETTER KEEP YOUR FINGERS CROSSED.