We all have, at some point of our lives, scraped our knees and elbows. What follows is the formation of a wound and its subsequent metamorphosis from one form to another, until it stabilizes into a dark and crusty layer. This layer, or scab, is a result of the recovery action of the blood platelets. These tiny particles form a mesh over the wound, and are glued together by fibrin.

However, the scab starts irritating the skin and the irrepressible urge to scratch at it, despite knowing that it would lead to pain and the tearing off of the protective layer, takes over. This happens to all of us. Let us try to figure out as to why the scab itches so much. Actually, there are many reasons that lead to the itching sensation, and it is hard to pin point any on of them for the irritation. On the contrary, these factors interplay and result into the twitching feeling. Histamine, a constituent ingredient of the scab, causes irritation to the skin under the scab and that touching its boundaries. Moreover, the nerve network around the wounded area, being ultra sensitive, may issue false triggers to the brain, thus initiating a response equivalent to the one produced in retaliation to itching. The tickling sensation is most prominent at the edges of the scab, because this portion forms the interface between the normal skin and the wounded skin. The irritation generally intensifies in the later stages of the recuperation from injury, as the scab prepares to come off the wounded part of the skin. The detachment of the crusty scab results in a distinct feeling of tickling mixed with itching.

Also, it is noticeable that scabs are particularly dry, and this dryness spreads onto the nearby skin area as well. Dry skin is more prone to give rise to an itching sensation, as compared to the skin with moisture content. Fidgeting with the scab generally results in the dismantling of the layer, and the contact of the exposed wound with air also intensifies the feeling of itching. Thus, it is strongly suggested that one should not scratch and scrape at the scab, as it is a natural response of the body to injuries, and this layer is destined to come off by itself. Any attempts to remove the scab through scraping invite infections and permanent skin marks. There are many anti itching medicines available in the market, and these are pretty handy in suppressing the itching related with scabs.