You need to consult a dermatologist and get investigated mainly your blood count, platelet counts, blood clotting tests, bleeding time and a
skin biopsy. Also
skin biopsy will rule out other causes like liver
spots or senile purpura.
Now coming to the treatment part, it depends on the confirmation of diagnosis. Till that time, you can take foods rich in vitamin C especially the citrus fruits like oranges, papaya, grapefruit, raspberries, blueberries, cranberries, and pineapple.