What in the world is it? Please read!!?

I'm 29 year old female and in good health.. so what is going on? This past month my body has itched from head to toe excluding female parts.. When I scratch where ever it itches a hickey mark appears and then a horrible purple bruise. My chest, my back, shoulders arms legs and belly are covered in bruises. What could be going on. Oh I haven't changed my washing powders or lotions so I ruled that out? NP bed bugs since it's only me that itches and not my boyfriend in our bed.. Please let me know what you think it maybe. I will be making an appointment. thank you in advance!