Speckle Bruise on Nine Year Old's Legs - Any Ideas?!

[MagicalMrsMistoffelees]

Can anyone identify these weird purple speckly bruises on my nine year old son's legs?! The first photo is the front of his left thigh and the second photo is the front of his right thigh.

They came up this afternoon at the end of a long day in the blazing sunshine - his school had an all day Sports Day. He doesn't remember injuring his legs and they don't hurt.

They're not the best pictures but hopefully they are good enough to comment!

They'll probably be gone tomorrow and I'm not worried but I've never seen bruises like them before!

I would keep an eye on them. Any spreading and I would take to gp as urgent appointment.

Looks like petechia to me - def keep an eye on it. It can be caused by lots of things including general bruising. I think it can happen with viruses too.
I'm not a doctor I should add so hopefully someone clever will come along and help.

Never heard of petechia - will google now.

I thought they might be something to do with being in the sun a lot of the day or dehydration but he seems in good spirits so not heat stroke. In fact, he's just headed off to football training the crazy fool!

I've had it from plastic bags round my wrist before but equally from low platelets when ill so keep an eye on it and if in doubt get it checked out. Of course it could be something completely different.

Bottom line - it could be anything...but I'd just never seen a bruise pattern quite like it and wondered where it could have come from!

The petechia definition has spooked me a bit but we'll just have to keep an eye on it and see how it looks in the morning.

I get bruises like these when I've grazed myself but not broken the skin.

Keep an eye for tummy pain and/or further brusing (below waist, possibly on arms, less likely elsewhere) and/or joint pain. They may be a sign of henoch schonlein purpura. He should be checked if any doubts as this can also in a percentage of patients also cause kidney issues.

Thanks for all the replies and things to watch out for, really interesting and helpful. He's had a busy day of sports, played an hour of football after school and wolfed down his dinner so I think he's absolutely fine but will definitely keep an eye on it.

This is a photo of the left leg again but with different lighting. The purple of the bruise is a more accurate reflection of the actual colour.

It looks nasty - was he sitting with his leg under a bench or something and it has rubbed? Wasn't meaning to scare you - I get it on my face when I cry (sob) too so whilst it can be serious it can also be nothing.

You didn't scare me. I know by putting the question out there I'll get a range of responses and I appreciate everyone who took the time to reply.

I'm sure the bruise is the result of some a Sports Day related incident. Will definitely keep an eye on it though as it'll be interesting to see how it heals.

I had something similar appear one evening and it was gone by the next. Dr thought it may have been a short virus or allergic reaction. Never happened again and never found out what it was. Always best get it checked.

Mystery solved - told me this morning he had been playing some game that involved smacking his hands on his thighs. 'Gun, Gun, Shoot' or something equally delightful. When I said that must be the cause of the bruising he looked at me sceptically. He hadn't thought that could be the cause as all his friends had been playing it too and they didn't have bruises.

Thanks for all the helpful comments and advice!

Haha. There's your cause right there!