Ds fell over a last weekend and grazed his knee, morning after the graze had turned into a yellow spot. I put a plaster on and it drew out some yellow and started to heel. A day later he fell again, grazing the same knee but a bigger graze. I cleaned it up and popped a plaster on. 2 days later he comes out of school with a new plaster on, saying it had been pussing. We get home and I have a look, there are several spots around the graze that look crusty yellow with another few yellow spots. I've been and got him some antiseptic cream which I've been putting on twice a day, but has anyone got any ideas what it could be? Is it worth seeing the gp?