Are Small Painless Bumps On The Penis Dangerous?

My husband has in the last 2 weeks noticed small bumps half way down his penis. There are about 10 of them, slightly raised, and a few shades lighter than his skin colour. There is no pain at all; would not even notice they where there without looking. They have not got any better or worse. Should we see a doctor? Is it something to worry about? What could it be?