These
spotsBirthmarks - pigmented
Liver spots
Measles, koplik spots - close-up
Mongolian blue spots are called petechiae. They can be associated with problems with blood clotting or with infection. The fact that yours apparently come and go suggests that your case isn't either a blood or an infection problem. In any case, you need to have blood tests to assess
plateletPlatelet associated antibodies
Platelet count function and clotting, and you should see a skin doctor as soon as you can arrange it. A skin biopsy may be needed to find out exactly what it is.
Best.
Dr. Rockoff