a friend of mine fell around noon today (tripped and fell on asphalt). The scraped their knee -- surface area of a little over a square inch. They flushed it with antiseptic and put gauze on it then.

It has still not scabbed over. They took the gauze off around 45 minutes ago, sprayed some more antiseptic on, and it has been open to the air since.

I don't know how concerned I should be on their behalf.