I have exactly the same thing. i have a few itchy spots at the back of my head and i can't figure out why. It is driving me crazy. I have to use a sharp object, such a pen lid to scratch it as my nails just don't cut it.

You are right, it could be the shampoo. I wonder if we use Neutragena (sp?) shampoo or an anti-dandruff shampoo, it may cut it??? I don't have dandruff and neither may you, but it is worth a shot. I'm going to buy some of that neutragena shampoo this week.

I feel like i have lice sometimes.