any idea what this could be?

Arady

on July 5th me and my kids woke up with some black marks that we first thought were a prank from my hubby since he's the only one that didn't get them and they looked like marker, they were painless, black and were disappearing, then 3 days ago I wake up to this rashes that are the black marks, they itch like crazy and feel like burns but my kid's ones disappeared.... any ideas?

Btw they appeared in the arms only