http://www.acne-web.org/rash-acne-buttocks/

What could the pimply rash on my buttocks be?
Yesterday i suddenly developed a pimply rash on both my bottocks. The pimples are raised, red, itchy and a little sore but do not have a definate head or any pus and dont really look like acne spots or ingrowning hairs.
They are located in a medium sized circular patch on one cheek and are sort of spread out on the other. I have never had anything even vaugely like this before.
What could be causing this? Is it a virus, infection, allergy or something else entirely?
Please dont just say go to the doctor, as i am already planning to go but unfortunately my appointment is not for sometime and i wanted some advice in the meantime.
It sounds like a heat rash.
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