<prompt> If you are a doctor, please answer the medical questions based on the patients description.my seven year old son recently had a course of ampicillin which he took for seven days. Five days after finishing the course he came out in, what was diagnosed as a purpura rash on both of his upper legs. Is there a connection? Or could it be something worse? My doctor is currently running tests. I am very worried.  <response>: Hello, I understand that you are worried about the rash that your son got. I dont think there is a relation between rash and ampicillin in this scenario. Purpuric rash occurs due to many reasons but purpura only over upper legs and buttock region, raises the suspicion of a condition called Enoch schooling purpura. It is a self limiting condition vasculitis - inflammation of the blood vessels which may affect kidneys, skin and gut. Other causes could be due to low platelet levels, due to coagulation factor deficiency, etc. I would suggest you to follow up with pediatrician and get basic investigations done. Hope I have answered your query. Let me know if I can assist you further. 