Mystery hospitalisation from when I was a child

Hi, I’m now 25 but when I was a child I was hospitalised for something I can’t match the symptoms to and have always wondered why.

I was around 5-7 l, average weight, maybe ate a little too much sugar but nothing crazy. Asthmatic, with dairy intolerance and hay fever but no real allergies.

Anyway, about 10 mins after my parents put me to bed, I started feeling aches in my legs. When I took the covers off to check my legs were covered in circular bumps and lumps.
When I got out of bed to show my parents, I fell over and couldn’t feel my legs fully or stand.
I army crawled into the hallway to shout for my parents and when they came over they took me to hospital.

I don’t remember anything about my treatment except for being asked to pee in a cup for a test.
I’ve just received a full copy of my medical records and it’s not listed anywhere on there. The symptoms don’t come up as anything on Google and I wondered if anyone might have an idea.