Weird rash/bruising?

[dontknowwhattodo80]

My 9 year old has come home from school with this weird mark on his arm ( near elbow). He says it doesn't hurt/itch and he doesn't know how he did it.

It's annoying me as I'm sure I saw something about patterned bruises recently but can't now find anything when googling.

Any idea?

Bump

Has it gone now? Looks like it could be irritation say from sticking plaster albeit an odd shape?

I bruise like this when I carry a bag in the crook of my arm

Google says it is definitely aliens.

Just being a generally clumsy person who has had all variety of bruises says that's a sharp table corner or door handle. Or looks like the edges of something, like he's had tape there and then taken it off.

Still there! No plasters involved but I am liking @Lightsong idea about a bag? Wondering if he's been carrying his rucksack oddly

I was just heading back having thought about a bag - is it that lovebitey rash type look?

Thats what mine look like, a lovebite in a straight line

I remember spending ages trying to figure out a weird line on one shoulder, and then I realised it was my backpack

I always carry shopping bags on my arm and every single time DP will say 'You're going to get that bruise'

Mystery solved- I think it's the Buckle on his rucksack straps!!