OTC allergy meds very reasonable to try.

Fun fact, liquid Benadryl (old school drug nobody uses anymore because it makes you sleepy) comes in a bottle that is sized to be safe in overdose for toddlers. I’m not recommending drinking a bottle of Benadryl. But I am saying poison control did tell me to do very little for a 2 year old that did (I was moonlighting as a rural ED doc at the time). In fact, they even told the parents not to bring her to hospital. I did an EKG anyways just in case she had an unrecognized heart issue that could possibly be revealed by the drug. She didn’t. But she did hallucinate and it was adorable.