In my case, my disease is primarily because I have this ITCH to start a new sweater, but I didn't have the appropriate yarn for what I wanted to do, I had to special order the book from my LYS (and not yet received it), plus not the money to purchase said yarn quite yet. Consequently, my Sweater Itch manifested itself as Start-itis.
(Also, since I was caring for Blue, I wanted something small that I could put down with ease. So, I thought I could suppress the Sweater Itch by just doing small projects).
I found myself wandering the depths of my Stash and, looking at all of the different yarns I have and not necessarily being particularly being inspired BUT wanting to knit. I surfed Ravelry looking at different patterns looking for inspiration.
Consequently, I started a two small projects to try and satisfy the Startisis from Sweater Itch, but to absolutely no avail. I started and finished two hats --- one for me, one for my Eldest Niece. (She has a thing for owls)
Oh, and then, because I've always wanted one, I started a crocheted ripple blanket, which I know is going to take me forever to finish, because I'm using left over worsted weight yarns from previous projects...and I have to stop frequently because crochet'ing for long periods of time hurts my hands.
And you know what? It still hasn't satiated my Sweater Itch.
The only thing that will satiate a Sweater Itch? Realizing that you actually DO have enough yarn for a sweater...just not the sweater you want....and starting your gauge swatch....
(Oh, and realizing that this very sweater was already in your Ravelry queue...and the stash yarn earmarked for this sweater....DOH!)