Around my skid burn on my leg from the concrete is a dark reddish and swollen down to the ankle, is it irritation? is it infected?

Possibly: You must have this examined by a physician who can see it, touch it, ask more questions and perhaps do further testing. The internet is not the place for this, and answers on HealthTap aren't intended for individual treatment, prescription or diagnosis.

Ouch!: Combination likely! Irritation, bruising, contusion, edema. Trauma hurts! If red streaking, fever, hot tissue may be infection also. Tetanus up to date? Allergies?