Cassie,
The hard truth is that there is just no way to know. ITP is just unpredictable. Once you have had it, even the acute form, it can come back any time in your life, even year later. Timothy has been all over the place. His Hemonc is perplexed. Of course he says Tim is extremely rare...his case, that is. His ITP started at age 11 and we were told it would likely never come back. He went into remission immediately after one dose of IVIg, for a year. Then he relapsed. Then he had IVIg again, three times and was found to be refractive to it. So winrho brought him up and he remitted for another year to normal counts. Then he relapsed. We did WinRho that time and IVIg and steroids. He was found refractive to all of them, but his counts came up to around 60k and stayed for a year. Then he relapsed again to where he is now and he is refractive so far to everything they have tried: IVIg, WinRho, Steroids, Rituxan, Promacta. So, you can't tell by trending up or down whether they are going to be acute or chronic. You just have to wait and see. Try not to worry about it. Just ride it out and let it be what it is. That way you won't drive yourself crazy with worry and you won't get your hopes dashed every time its not what you expect.
That's how we ride the roller coaster.