Comment by giardini | Hacker News Reader

Comment by giardini | Hacker News Reader

From the article: "“It is a known observation among the vulgar that the saliva is efficacious in cleansing foul wounds, and cicatrizing recent ones,” wrote the 18th-century physician Herman Boerhaave. He was correct. Wounds that would take several weeks to heal on one’s skin disappear in a week inside the mouth."

But the author of the article (not Boerhaave) seems to be missing several points:

1) a wound inside the mouth is protected by tissue all about, and body temperature is maintained as well. An external wound is ~half open to the world and has no temperature maintenance on the open surface. Temperature is important for the immune system to perform.

b) concerning the phrase "saliva is efficacious in cleansing foul wounds": what Boerhaave is saying is that licking one's wounds is efficacious. He's not merely speaking of saliva floating about a wound inside a closed mouth. The common phrase "to lick one's wounds" is not a false euphemism and is not limited to animals other than humans. Licking a wound can help heal it, sucking a wound can remove material that has been inserted into a wound and can quickly route fresh blood to a wound site, aiding healing and flushing out foreign material.

https://www.quora.com/Does-licking-your-own-wound-help-heal-...

https://www.sciencedaily.com/releases/2008/07/080723094841.h...

http://www.science20.com/news_releases/histatin_why_licking_...

The tissues inside the mouth are a form of mucus membrane. The skin is not. They are different tissues. It is disingenuous to frame it like they are the same type of tissue.

This is key. It's like saying a bones takes months to heal, but skin heals in weeks. Different tissue, different healing process.

My personal experience with licking my wounds, after two decades under the assumption that it would help: it gets infected and then scars badly. N = 1, but admittedly a very pertinent sample, at least for me :p

Placing an Activ Flex by Band-Aid on a skin cut seems to act as a true temporary replacement "second skin", and the cut heals far more rapidly then a regular band-aid. It heals in a similar time-scale as this article says is regular for the mouth.

I'm sure there are other brands or technologies that act similarly, but once I found this particular type of bandage I never had the thought of using anything else.

While true, the reason covered skin wounds heal faster is often due to the cover stops the drying out of the wound which slows healing.

Thank you. Though, I wasn't implying these bandages have spit in them.

A Tegaderm has a similar effect on small scrapes and burns. It seals in a lot of the moisture while still allowing you to sweat through it. I still irrigate the wound thoroughly before bandaging, but it's nice not having to change dressings while the wound is healing.

https://www.3m.com/3M/en_US/company-us/all-3m-products/~/Nex...

That's good to know. Thanks!

While not an expert on this particular science, I noticed that the look of the applied bandages is entirely different. The BA bandage puffs up with moisture, while the Tegaderm visually seems as if it only creates a seal.

That's true. The tegaderm doesn't wick or remove moisture. It simply provides a barrier while the wound is healing.

I would have just assumed that the major factor is that your mouth is full of fast-dividing cells. In short, the lining of your mouth is constantly replacing itself, which is great for injury (and withstanding enzymatic action of saliva), but it’s also why chemotherapy causes so many problems in the mouth and GI tract.

Agreed, and presumably there's evolutionary factors here too. If you can't eat you die - having a wound in your mouth that reduces your ability to eat is not good, so there must be strong selective pressures for tissues that can regenerate rapidly. I guess the selective force in the opposite direction might be the caloric demands of healing, hence why we don't regenerate too rapidly.

That, and the blood supply. The inside of my mouth is a sort of lurid pink, because all the tissues are packed with capillaries. Meanwhile, my skin is a barely pinkish off-white, because what blood vessels there are are deep below layers of cells and connective tissue.

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