I used to work with insulation, same senerio(sp), small fibres. Take a cool shower first to wash it from your skin, hot water opens the pours allowing the fibres in. Also baby powder works good to keep this from happening. Put the baby powder on liberaly BEFORE hand. I now these are preventitive measures, all I can say is don't scratch it. Makes it worse.
Itch on my friend, itch on.