Hi Beck459
If the marks are fairly well defined, as you seem to suggest, it seems unlikely they are there by chance. However, some people artificially mark hogs to help them to identify a particular hedgehog – unnecesary in my opinion as they all have their own natural markings/characteristics. But that is a possibility. If so the marks might gradually disappear, i.e. if it rains.
Having said that, and it’s not my area of knowledge, but hogs do sometimes get skin problems – for instance ringworm – and if you are concerned that might be the case you might like to take advice from your nearest hog carer/rehab. You can get contact details by ringing BHPS on 01584 890801.
I hope the hog is ok. Good luck.
