hairy dilemmas

We've been having lots of drama over the past couple of weeks regarding Lizzy's mane.
The trouble with tresses started when she arrived home from school one day with what looked like totally ratted-out hair. She was asleep, and I assumed that Matt had had the windows down, and then her head slid around on the seat.
We didn't wash her hair that night, and by the time we did, it was in unbelievable condition. I had to keep applying handfuls of conditioner and running my fingers through it again and again, while she screamed "NO! NO!" and Maddie shrieked in the other room (Matt was trying to pacify her while I dealt with Lizzy's hair). If we were still in an apartment, I'm convinced the authorities would have arrived by the end of the shower.
Afterward, I sprayed copious amounts of detangler into her hair and combed it out. Problem solved! Except, it happened again (to a slightly lesser degree) the next day. What on earth?! This has never happened before. What was different?
Parenthood feels like an exercise in problem-solving so much of the time. Often when one's child is too young to verbalize its symptoms, but a good deal after that stage, as well. This time, I realized somehow that, irony of ironies, it was the detangler itself that was the culprit. I'd used this brand before (rhymes with, ahem, Schmanteen) with success, but this batch, for whatever reason, was stickier. But not enough so that I noticed when I applied it. So that junk got tossed.
This week's issue is ... I'm almost afraid to say what I suspect. But Lizzy's been scratching her head vigorously all week, and I'm concerned that it might be *wince* LICE. I haven't heard anyone at school or church say there's an outbreak, so I don't know where it would've come from. And on the eve of first grade. Not great timing.
I've halfheartedly looked through her hair a couple of times, but a) I'm not sure what I'm looking for, besides some kind of little bug, which I haven't found, and b) I kind of don't want to find anything. But the scratching continues. I'm scratching my head a little more these days, as well, possibly psychosomatically.
I'm not entirely sure what to do at this point. I know there are shampoos, and fine-tooth combs, and much washing and bagging of sheets and pillows and mattresses, and I'd soooo like to not bother.
It's odd to me that the baby herself is supplying the least drama around this house these days. (knock on wood) (prayers that it continues to be so)