Why do scabs itch?
Actually, scabs don’t itch. Scabs are just crusts of dried blood and fiber that cover a wound. It is the wound that itches. In the healing process, some of the nerve fibers that mediate both pain and itch become irritated and inflamed. This process leads to the itch we encounter. This “itch” is actually a small pain. If the wound were deeper, we would then experience frank pain. So what happens during the recovery period to irritate nerve fibers? Well, wounds repair themselves and shrink in size, partly because of the elasticity of the skin but partly because the scab pulls on the wound. Itching can also be caused by infections or small cracks in the scab as it dries. That is why some dermatologists treat wounds with moist dressings, allowing the wound to heal without scabbing.
As the wound heals, the scab starts to detach from the healed portion. This separation process stimulate the nerve endings. Since some areas under the scab heal faster than other parts, it is not wise to pick on it until it is completely ready to come off. However, that is easier said then done. It’s important to keep the wound clean, and if you do remove the scab and expose any unhealed area, be sure to put an antiseptic on it and allow another scab to develop.