What Causes Spots With Yellow Head On Legs, Abdomen And Arms?

Hello I am a 14 year old woman and I'm 8 stone I'm 5 foot 6 and I'm generally a healthy person I have recently had toncilitous. Ut I have got over it now but still on antibiotics. I have spots on my legs, lower abdomen and arms. They feel like bruises and occasionally they form a yellow spot head. I developed the tummy ones yesterday and since then I have developed them in various places please help. xx