system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do scabs get itchy?

Is it not counter intuitive that the scab, which is part of the healing process, is really itch while your skin grows back?
gpt
There are several theories that explain why scabs itch. There are histamines in scabs that irritate the skin around the wound. Some doctors think this is the body’s way of getting rid of the scab which is no longer needed. When it itches, you scratch it and it is comes off. There is a flaw in this theory, because sometimes the scab itches before the wound is healed.

A second theory has to do with nerves in your skin that are cut when the skin is cut. When a wound is healing, the new skin is very thin, so the nerves are even more sensitive. As they are healing, their signals may be affected and the brain gets the wrong type of signal. The brain may interpret it as an itch and want to respond by scratching it.

Another theory is that as the wound heals, the scab pulls on the new skin, and that causes the area around the scab to itch.

Lastly, dryness could be a reason for itching. When the wound occurred, the skin, nerves, and oil glands were affected, and without oil, the skin would become dry.