[ramanand]

It is often observed that there is itching when the wound is at the final stage of the healing.
what cause that itch?
Do this itch has any evolutionary advantage?
Or is itching plays any therepeutic role?

[freeztar]

A quick search on google provided many different answers. This one seems to be the most logical to me:
Singapore Science Centre: ScienceNet|Life Sciences|Physiology


I don't see how it could be evolutionarily advantageous. It's more just a byproduct of physiological processes.

Hope that helps.

[mynah]

Though it may be purely coincidental, scratching due to itching could help get rid of the layer of dead - and, in some cases, infectious - cells.

[freeztar]

Originally Posted by mynah

Though it may be purely coincidental, scratching due to itching could help get rid of the layer of dead - and, in some cases, infectious - cells.

Yeah, I thought of that but ruled it out as being advantageous because it can also introduce new infections. In this case, it's evolutionarily neutral, but there might be something else I'm overlooking.

[Boerseun]

A very good question, indeed!

Also, keep in mind, that during 99% of our tenure here on planet Earth, hygiene was in such a state that our nails were considerably more dirty and cracked with sharp edges than it is today. A perfect place for cooties to grow! Which isn't exactly the best tool to scratch a semi-healed wound with.

That being said, would you say there's some sort of a connection between chewing your nails (a particularly nasty habit, but one which is evident accross all cultures) and wound-scratching?

Can it be that nail-chewing isn't the manifestation of psychological insecurities we see it as today, but merely a throwback to that 99% of human existence in which nail clippers didn't exist - in order not to kill ourselves scratching itchy wounds?

Maybe we're wired to chew nails...

Interesting. Very, very interesting...

[ramanand]

Pain mostly serves a protective function. For example, if we sprain our ankle, the pain we feel is almost immediate. It tells us that we have done damage to our body, and it deters us from putting more weight onto the ankle. This minimises further damage, thus protecting the body.
Itching is a built-in defense mechanism that alerts your body to the potential of being harmed. In this case, it might be the potential of being bit by a bug. As soon as we feel an itch, our first natural response is to scratch the spot of the itch with our fingernails. The reason for this response is simple — we want to remove the irritant as soon as possible
Itch was long considered to be a mild form of pain describe, but came to be recognized as a distinct sensation,
I mean something during the course of evolution had happened that has made this itch to exist,

[koji8123]

...............................

[mynah]

Dogs' licking their recovering (and presumably itching) body parts seems to promote healing. We are rather Johny-comes-lately primates who are more adept at using our fingers than bending down to lick whatever itches (imagine licking some of the parts your dog habitually licks in a meeting or rush hour traffic). As a result, we may represent an evolutionary offshoot that is less equipped to deal with the itching response in the natural way, and had to come up with antibiotics and antiseptics instead.

[Moontanman]

Originally Posted by mynah

Dogs' licking their recovering (and presumably itching) body parts seems to promote healing. We are rather Johny-comes-lately primates who are more adept at using our fingers than bending down to lick whatever itches (imagine licking some of the parts your dog habitually licks in a meeting or rush hour traffic). As a result, we may represent an evolutionary offshoot that is less equipped to deal with the itching response in the natural way, and had to come up with antibiotics and antiseptics instead.

Hmmm..... Imagine in a meeting or while walking to the store, oh yes!!! Actually if you think about it if humans could do that we probably would with no more shame that our dogs do. If we could we would and it wouldn't be such horrible thing to us. But i do think the idea of this being an impetus to use plant (antibiotics, medicine) material to heal is interesting.

[modest]

My guess would be parasitic insects. Ticks and other kinds of blood suckers. How else is an animal going to remove such things but to scratch? Seems like a normal evolutionary development to me. Think about what an elephant has to go through to keep that stuff off its skin - rubbing its back end up on everything. The wound relation is most likely a side effect. Pain would prevent an animal from scratching a very bad wound - in which case licking does seem to be the preferred thing to do.

~modest