Steriods, long-term in large doses, are not good for the body (unless needed to deal with something even worse for the body) and can cause physical and behavior changes and sleep disturbances. But sometimes they are the best alternative, since other drugs also have potential side effects, and the sprays (nasal and lung) are tiny, focused doses, placed just where they are needed. They calm/soothe the tissues locally, and little-to-none makes it into the bloodstream.
I haven't had to give steroids to kids, but have used the lung inhaler daily, and the nasal spray occasionally, for over 15 years. I might not be alive without them – I have had unendurable side effects from almost every other drug I've tried. I have never had a noticeable side effect from either steroid spray.
Every person is different, and what works for one will be a bad solution for someone else. If my kids were suffering, I'd try pediatric doses of a number of things, as recommended by the doctors who have the training. Most of the time, a drug is dropped or reduced after the symptoms are under control, and if undesirable effects begin to show up, a medication is dropped or exchanged right away.