Cold sore ?

Looks like chickenpox check rest of his body

He could get more maybe the start off it ' just look similar esp the one on his lip really looks like a chickenpoc thats starting to blister ' but id give gp a call to double check incase it is Coldsore as they can be quite bad for babies but im thinking chickenpox x

Looks more like hand foot and mouth to me, mine started with a few spots like that and ended up in mouth ulcers and a very bad nappy rash. She only got a few spots on hands and feet

My LO gets the odd spot like this and they usually go within a few days x

Looks like HFM to me personally. My oldest never broke out too bad. It was always only her hands feet & mouth area. & never as bad as everyone says theirs is which is so weird to me. But non the less my kids pedi would state it had to be bc it was on her hands feet & mouth lol. I think it's just different for each kid. It can be slow, little then grow like a wildfire all over their bodies or I think it can also be minute & minor looking but still HFM. My oldest around 3 also had it only inside! That was crazy. She was sick. Couldn't figure out what it was. The doctor did a small scope in office & confirmed she had HFM in her throat & bum lol