I would definitely go back to see your primary care doctor
about this as soon as possible. Unexplained bruising is always a symptom that should be investigated carefully to make sure there is nothing serious going on.
Some of the most common causes of unexplained bruising include problems with the blood clotting system or a drop in the platelet count. These can come on suddenly, even if you were previously health and had normal blood work in the past. Your doctor will probably want to repeat the blood work.
Itching and bruising together can, sometimes, be a sign of a serious problem with the liver. When you go to see your doctor make sure to mention if you have recently taken any new medications, or if you have any other symptoms such as yellowing of the skin or eyes, abdominal pain
, or changes in the color of your urine or bowel movements.
Finally, itching with bruising may be a sign of a local skin reaction. For example, a bad case of hives
may sometimes result in a color change in the skin that resembles a large bruise.
Regardless of what might be going on, the first step is to see your doctor!