We've used it under medical supervision with our DD when she had her first allergic reaction at 7 months old. We were monitored closely while using it though, for both the reaction and the phernergan. Wasn't an issue though as it made her hyperactive rather than have any sedative effect.
Your poor little poppet. As BlackCat says, for some kids it seriously knocks them out but others go a bit hypo. My 5 year old had some earlier this year for a very bad eczema thing (geez, I sound like I drug my kids all the time!), and she didn't sleep for aaaaaaaages. Not much you can do once she's had it of course, but just be prepared that you might need some late night tv viewing ;-)
Its so hard when there almost always seems to be a big downside to any kind of medication you give your kids.
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