Why do injuries sometimes cause itchiness?

General Questions
#1

I fell and hit my butt on some ice a few weeks ago. The first few days I was sore, but within the last week there’s been no soreness but some itchiness.

I’m not asking for medical advice. It’s not severe, and I don’t need a doctor. I’m asking out of curiosity.

#2

Did you scab? It is my personal speculation that scabs are rough and poke into tender, newly forming skin causing itching. if you have scabs, soften them with antibiotic cream.

#3

Injured cells release histamine, so you itch.