About 15-16 years ago I was on this discussion group every day (thanks to everyone that got me through those days of worry). Our son (17months old at the time) woke up with huge bruises on his body in the strangest locations. His pediatrician knew what it was right away and after a blood test, put our son in to the hospital (ITP, 2000 platelets.) In the following two years our son was admitted into the hospital 18 times to receive IVIG. All of his childhood immunizations were stopped. Over time, as we got use to ITP we realized our son (and our family) would be ok. We would live with it. Entering his third year (with a label of being "chronic"), his platelets started to rise. And rise and rise. By 4-5 years old, his levels were normal. Over the years he received all the required immunizations except the 2nd and 3rd dose of MMR). He handled them all well.
Three years ago we booked a trip out of the country. He received the typhoid, hep A and yellow fever immunizations and did fine. But, the doctor wanted him to get MMR since the number of cases of measles was rising in the US. After research, we decided he should get another dose. One day before our trip we had a blood test just to confirm that he tolerated the shot. To our surprise he only had 3000 platelets!! Oh no! back to ITP - although it was not idiopathic. Seems he reacts to the MMR vaccine. After another 2 years he is completely recovered (and thankfully, he did receive some immunity to MM & R from that dose of the vaccine).
I know not every child or person will experience a recovery or remission but even when we thought that ITP would be our life journey we began to realize that our son would be okay. I just wanted to offer our story if you need a little hope today. PS - that toddler is entering college this summer!