Welcome to HCM.Redness
might be after some blunt injury
or due to continuous pressure during sitting or some work.
Apply ice 3 to 5 times a day.
Start nsaid with serratiopeptidase
You can apply elasto bandage during walking,movement.
Avoid any extra movement,sports activity till get complete cure.
It will subside within 3 to 5 days otherwise consult your family physician for proper diagnosis and medications.