Location: Brisbane, Australia
I first thought it looked like a brown recluse spider bite, but apparently we don't have them here. At least there have been no documented bites from a brown recluse in Australia ever.
It's been there for about 24 hours, I suppose, and it's very itchy but the itchiness comes and goes. It's not sore.
I'm on holidays so I've been spending a lot of time in bed, so it's unlikely to be anything from outside.
What is it and how do I treat it?
Last night: https://41.media.tumblr.com/47ca8543887e791dd9b7c73fae526ce4/tumblr_o4rq5a3gqn1s14h8go1_540.jpg
This morning: https://41.media.tumblr.com/1eb3f03ec76a3ff1fbe68bc23a68d5c1/tumblr_o4rq5a3gqn1s14h8go2_540.jpg