My 13yo noticed a sore red patch on his ankle a few hours after we'd been to the park yesterday - I assumed he'd rubbed it on his trainers or something in the playground, but later on I noticed a tiny black dot in it and thought maybe he'd been bitten or something. It hurt a lot to touch, although he is autistic and sensitive/nervous around pain. This morning he said it hurt to stand on it but he been fine getting around all day so I think that was just when he first got out of bed. It's still been sore to touch but nothing too bad so we haven't paid it much attention during the day. This evening he took of his sock and said it was bleeding - there was what looked like fresh bright red blood on it, so we thought it must have been knocked and "burst" at some point. I got a damp tissue to clean it up (he did it himself as it still hurt too much to touch) but no blood came off. We left it for a bit and tried again, still no blood came off. Before he went to bed I thought I'd have one more try but with an antiseptic wipe - I watched him wipe over it a few times, not a bit of blood came off. So I tried to take a photo, because now I'm concerned that it isn't a bite that has "burst" and that the blood is a sign of infection or something. He's fine in himself, no temperature etc, it just still hurts to touch it, and a little bit around it. I'm going to keep checking on it through the night, but wanted to see if anyone has had anything similar? Photos attached, not the best quality - the first two "normal" ones are from last night, and the bright red ones are from this evening. Thanks in advance for any advice, and sorry for any typos from my phone keyboard!