Aibu to be worried about permanent damage?

[Nearlyhaveahouse]

Disclaimer : I'm going to a doc about this ASAP but need some hand holding till then!
My son is fair haired but tans easily. I usually use factor 50 anyway. However he's been taking sun cream to school and I'm not sure he's been using it. At home I opt to use suncream less and stay indoors at peak times or cover up.
I thought his neck was grubby but on closer inspection he's got a dark brown mark in one side, like he's tanned too dark on one patch.
I'm freaking out that he's got permanent damage (I know that even a tan is a sign of damage but I mean more extensive).
Anyone else had this after sun exposure. My other kids, same colouring are fine. First time it's happened. He's not been burnt at all during this hot weather either.
Really worried

He's probably just caught the sun more on one side.

I wouldn't worry, its tanned rather than burnt, he will have been building up the tan gradually.

It could be a concentrated patch of melanin that goes darker when exposed to sunlight.
Im quite pale and freckly, and I've got an area on my arm about 5 by 7cm that goes much darker than the rest of me.
Try not to worry, some people just have a lot of melanin and tan a lot easier than others.

And I wear factor 50 and have not burnt at all this year, but my arm patch is definitely showing up.

Thank you. Thats encouraging. I've seen sun cancer first hand and always think I'm really sensible. This threw me.

I've had serious sunburn and went to hospital, my skin very red and blistered, which burst and was weeping and was extremely sore and uncomfortable. No permanent damage.

Don't worry about it - your son is just a bit tanned. It doesn't sound like it's damaged at all.

Seriously, please don't go and see a GP for a sun tan!!!