Flaky, dandruff like lumps on bunny's back

[Theodore Leonardo]

So as we all know it's malting season right now, and Theo is quite the malter... but as I was grooming him the other day I felt a lump on his skin and on further inspection found a crusty patch amongst the fur. I assumed it must just be a patch of tangled fur and thought nothing of it, but I keep finding more patches as the days go on and I'm not sure whether this is normal during malting or if it's a cause for concern?

I'm a bit overprotective of my little bun, and quick to rush him to the vets over the slightest thing, but I'm trying to be a bit more rational now and not jump to the worst conclusions. I actually took him to the vets recently due to changes in his behaviour and the vet said he seemed in good health and it must just be a behavioural thing. Unless he missed something?

I'll try and attach some pictures asap to give you a better idea of what I'm talking about

 

[Theodore Leonardo]

Sorry for the rubbish picture. So far I've counted 5 like this, but I suspect there's more I haven't found yet.
Any help would be much appreciated!