What Causes Small Red Bruises On Legs And Arms?

I was recently sick and started taking antibiotics (ciprofloxacin). A few days later I broke out in a rash, although it wasn't itchy or raised. It just looked like little red dots all over my body. When I went to urgent care they said it Psoriasis but chuckled and said he could possible be wrong. I then made a same day appointment with my dermatologist who also didn't know what it was and gave me a cream to put on it. The rash is on my legs and feet. My feet are just small rash like while my leg looks like bruised rashes. they are now spreading and i went back to my dermatologist who gave me Halobetasol. Is it possible to be allergic to the CIpro?

Background information: A week prior to that we went to a lake and after researching we thought it was possible it was Swimmer's Itch as that is what the rash looked like in the beginning but now it looks like ALLERGIC PURPURA. Sorry I research a lot.