During flares we loose hair as a delayed-reaction, even those of us who do not take any medications suffer from this. Hair regrowth is a delayed reaction to healing from our flare. Hair loss is often associated with anemia, low vitamin D, and nourishment all things that are common during our flares. Hair is expendable, it takes a lot of energy to grow and during times of health troubles our body stops growing hair, it begins falling out. Once that stress/undernourishment is over, hair growth resumes.
A good watch:http://www.med.umich.edu/ibd/school/video205.html