Hello, everyone

I have crazy petechiae situation and need your opinion. I initially got petechiae (a few dots) on my calves (both legs) after I tanned by the pool 2 weeks ago. It was very hot that day and I used a sunscreen oil that I never used (maybe that’s what caused it but not sure). In a week petechiae spread further up my calves and inner thighs. I went to see a doctor on Tuesday, he said that it looked like vasculitis. He took my blood and very thing was normal except for PTT, it showed 34 instead of normal 33. However, I knew my entire life that I had high PTT as every time I got a small cut, I would bleed for quite a long time. Anyways, based on this, the doctor prescribed prednisone and I started taking it yesterday. Today my petechiae got worse!! It’s now spread all over my calves, feet, toes and went further up my thighs! Does anyone have an opinion as to what’s going on? Do you think the doctor prescribed me with the wrong medication?