I've never had petechiae before, however in the last 3 months, i've got it twice from scratching, once (all over face) from vomiting and another time widespread on arms and legs spontaneously. fbc normal besides high trans sat iron. any other ideas?

Vomiting can cause petechiae if it is particularly forceful. If you continue to have petechiae spontaneously, you should see a hematologist to see if there is any blood abnormalities that need to be treated. Another avenue would be to see a rheumatologist to see if there is any autoimmune issue. Good luck to you!

Iron overload can be a cause of increased capillary fragility & easy appearance of petechiae. Have you noticed any changes in skin pigmentation that hemochromoatosis may cause? Vitamin C deficiency can cause increased capillary fragility. Consult a hematologist for evaluation & appropriate testing if frequent petechiae occurrence persists. In the meantime try taking a vitamin C supplement daily.