My wife, Elenor, and I didn’t realize our son was having an allergic reaction until we noticed Harvey was scratching himself to the point of bleeding.
Then he got a rash around his mouth and his ears began to swell until they looked like two mini brains attached to his cute toddler head. It was the combination of that and the voracious cough that, we’d learn later from the allergist, classified his reaction as anaphylaxis.
He is allergic to cashews and pistachios (a common coupling, evidently), so he was prescribed epinephrine injectors to use in an emergency.