Could a hormone imbalance cause keratosis pilaris to get worse or flare up?

Probably: Keratosis pilaris is a very vexing problem that we do not have great answers for. However, many patients note large fluctuations of their kp during pregnancy, and some have found that it is better or worsens after starting and oral contraceptive pill. So probably there is some relationship between hormones and kp, though I am not totally sure how they are connected.