If our skin is itching, we scratch - and rub in dirt and bacteria. Why did nature invent itching at all?

Scratching is kind of nice at first, but on the downside it tends to aggravate the skin. In combination with mosquito bites or neurodermitis, to name just two examples, things are usually getting worse before they get any better. Could anyone think of some superior purpose lying within the concept of "itching", rather than simply sticking with the good old "pain"?

If our skin is itching, we scratch - and rub in dirt and bacteria. Why did nature invent itching at all?
Well, three quesses.


According to your hypothesis we rub in dirt and bacteria, so maybe nature is doing this on purpose to make us get bateria on us to build up our immune systems.


Or maybe there are chemicals or enzymes in things that bite us or touch our skin (like being allergic to metal) that cause the itch.


But I think the most popular answer to this queston would have something to do with the fact that during a months time your skin is completeky recycled meaning, the layer that was on the very bottom at the begining of that month is now the top layer of skin. You itch because dead skin is needing to be scracted off.
Reply:It alerts the body that something is going on and should be taken care of. There is no other superior reason behind it other than a reminder that it itches and you should find lemon or salt, or whatever you have around to neutrilized the effect.
Reply:its an evolutionary thing i guess. plus itching can make u get rid of stuff on ur skin that cud harm u, it doesnt always rub it in.
Reply:Histamine is released as part of the imflammatory response. This makes the capillaries more 'leaky' so white blood cells can leave them, thus reaching the site of infection so they can start the immune response.


It is histamine which causes the itching, hence the reason why anti-histamine cream is effective on bites.
Reply:I've also thought about this... superior purpose...as to why we scratch. I'm thinking that it might provide a beneficial increase in circulation that aids healing.





For the insect sting/bite it may help to dissipate the problem. For neurologically stimulated itching--no clue as to a beneficial effect.





If you think of it, most of our actions and reactions were born of survival necessities to benefit us until we procreate.





I don't know, this seems a rather subjective "science" to second-guess why we have or do this or that. What is the appendix for? Why do we sneeze when we look at the sun? Why does your little finger hurt when you bump your elbow? --but it's lots of fun. I think it gives insight into our ancestors' tribulations as well.





Good luck on getting an answer you like.