What Causes Purple Bruises On Chin, Neck, Leg And Scrotum?

My grandson has various symptoms that seem pretty serious and was finally taken to childrens hospital for tests and they were inconclusive. He is being sent to a hematologist and rheumatologist for further testing. It started a rough winter where he was constantly sick with colds and such after they gave him a bunch of immunizations to catch him up. Then he would get rashes on his face with tiny flat red spots that don t dissipate when pressed...now a couple huge purple bruises on his chin and some faded on neck and one on leg. His penis spontaneously turned red purple along with his scrotum but that has healed. He vomits on and off. His energy is low and is content to just lay and stare at the ceiling a good part of the time. He only has a few words at age 2 and has a white coated tongue with some whitish sores on the sides of tongue. When he was born he was pretty much bruised from head to toe and was jaundice and needed to stay a couple extra days on a light table. Docs have been stumped. Any ideas? No fevers with this bruising but he will cry on occassion as if in pain. He can t eat citrus cuz he throws up. Is it possible he has vitamin C deficiency? They labeled him as having purpura at childrens hospital but told her they didn t think thats what it was. All tests normal except slight inflamation elevation.