Excema like red patches appeared from nowhere on 4 y o ds - what is it??

[bobsmum]

DS is 4 and has no allergies that I know of. In the last couple of weeks he has developed dry patches of skin on his elbows, knees and cheeks which have now turned red and sore looking. From the very little I know of excema, it looks like that. He's not compaining about them, but they look pretty strange as they've just come from nowhere.

Any ideas? If they're not bothering him should I bother the GP? Or could it be something infectious?

Could it be impetigo?

Have heard of it - what is it?

Psoriosis maybe?

Have just looked up impetigo - the pathces aren't weeping or crusty, just red and dry.

Off to look up psori....if ican spell it!