Is this normal for a scar?

[the_midnight_faerie]

This may be absolutely nothing, but I cut my arm the other night and now the scar their is very, very red and risen incredibly. It's kinda enflamed and itchy...

I know that it is most likely nothing, but none of my many scars before has ever done that. Could it be infected? And what should I put on it?

[flying[star]]

I doubt an old scar could be infected.
If it's newer, you may have opened it up slightly and caused irritation, but it doesn't sound like an infection

[Bitter_Angel]

Sounds like this might be turning into a hypertropic scar, this is where the scar tissue forms bigger than the actuall scar. its nothing to worry about but it will probably leave a worse scar than others you may have.