"Medical Definition of induration. 1 : an increase in the fibrous elements in tissue commonly associated with inflammation and marked by loss of elasticity and pliability : sclerosis. 2 : a hardened mass or formation."
Induration | Definition of Induration by Merriam-Webster
I guess (unless it is examined surgically) only time will tell if this is what it is and it will otherwise heal.
- And got the T-shirt