Hi,
I wonder if anyone has ever seen or had similar.. My 6 year old son has eczema and has had it since a baby... twice this year his hands have broken out into spots.. almost like teenage zits...
Our doctor was totally baffled and gave him antibiotics.. the second time they broke out even the dermatologist said she hadn't seen anything like it in her time...
Each breakout lasted about 2 days.. Each time his hand swelled up and he couldn't really band his fingers too much but as I said couple days later they were back to normal... Has anyone had similar experience that might know what causes it?

YES! I had the same thing on my hands from the ages of about 12-18, a little older than your boy but sounds like the same thing. Mine was caused by heat, I found that in the cooler months it wasn't as bad. I used a cortizone cream several times a day and kept the affected fingers bandaged, it took about a month but it healed completely.
As for keeping it away I can't really help you, mine seemed to clear up on its own and I'm now 23 and haven't had a about for years.

Could this possible be pustular psoriasis and not eczema? Something to ask your pediatrician about. Sorry that I can't help with a treatment.