My 4 year old grandson has been given pediatric zyrtec for what seems like allergies. He has been so unhappy and angry now, tantrums, etc. He has now started to open his mouth in a weird way as if his throat is itchy and is getting very twitchy with his legs. He has a tendency to hold it when he has to go to the bathroom now as well..
Hi.by what you quote I feel that your grandson is having temper tantrums, and it is quite normal in this age group. It may persist till 5 years of age. But what you can do now is avoid giving importance to that behavior when he does that because mostly kids do this for attention seeking and if you give attention they will over do it. Hope my answer was helpful for you.  I am happy to help any time. Further clarifications and consultations on Chat Doctor are welcome. If you do not have any clarifications, you can close the discussion and rate the answer. Wish your kid good health.