Those who have had prior experience with such reaction may have an epinephrine kit. Access to this medication is by prescription only. It is the only thing that can save a severly allergic victim. The cut has healed, however, the skin around the wound has hardened and discolored slightly. Scar tissue is forming.
Scar tissue is stiffer and harder, than normal skin.
So in this case it probably is scar tissue. The big concern with any cut is infection. I've heard conflicting amounts of time. Anyone who has never been immunized for tetanus should be given one immediately. Generally, everyone needs a booster every ten years, unless they have a very dirty wound and the booster is over five years old.