Bumps on edge of penis head

Let me preface this by saying that I masturbate once or twice a day every other day. Sometimes I don't use lube. Okay, so I noticed a little while ago that these small white bumps have shown up on the edge of my penis head. What are they/should I be worried?

You can upload pic from chat box via pc or upload via any image hosting website and give the link 

You can upload pic from chat box via pc or upload via any image hosting website and give the link