I had a rash by my armpit which appeared last Friday. Since then each day I've been gaining another small patch on random parts of my body. I also broke out in a coldsore for the first time in years this week (not sure if that's relevent). I don't think it's an allergy as the ones on my arms/hands weren't touching any clothing when they started itching.
I now have one on my face, one of my calf, one on my hand, on my throat, one on my forearm (pictured). It's starts with a scratch and a few minutes later there's lots of tiny bumps.
Any idea what it is? It's not been going down, the one under my arm is still the worst one and is bright red and sore.