Will Daily Flonase Stunt My Child’s Growth?

Is daily use of Flonase harmful for my 7-year old? My daughter’s allergist recommended Flonase to replace Zyrtec, and it’s actually done wonders. But my husband cited a study that long-term daily use of Flonase can stunt growth in kids. Of course I plan to ask the allergist at our next visit, but this is causing a lot of drama between my husband and me right now.
—Just want my daughter to stop sneezing

As a parent of an allergic child, I feel you. The study (thanks for sending it) is a randomized controlled trial evaluating changes in growth speeds for children who are randomized into either daily use of a Flonase product or not. You might ask why we would think Flonase would reduce child growth — is there any theory for this? The answer is yes: Flonase is a steroid, and we know that (for example) kids consistently taking steroids orally will lower their growth trajectory. Zyrtec is an antihistamine, not a steroid.

This is a very well-done randomized controlled trial. The sample is relatively large (186 treatment, 197 control), and the children are followed over a year. The authors collect data on height at the beginning and end, which allows them to look at growth rates.

The treatment group in the study grew more slowly. The effects were fairly small — 5.46 centimeters versus 5.19 — but they were significant.

I am always loath to say that people should worry about something that maybe they were not worrying about before, but this study is strong enough methodologically that I think this is a consideration you should take into account. It isn’t obvious to me (or the study authors) that the benefits do not still outweigh the costs. But the effect on height seems plausibly real.