For Two Days I Have Had A Breakout On My

For two days I have had a breakout on my neck chest and back that almost looks like acne. Small white heads. No itching. They go away when popped but others show up. I have adult acne so I thought it was just acne. I also have sensitive skin so I thought maybe it was just a minor rash so I took Benadryl. I have had chicken pox as a kid so I know what they look and feel like. I do not believe its that. Any suggestions?