My Son, 8 Years Old, Was Stung By A Bee

My son, 8 years old, was stung by a bee yesterday afternoon. He does have allergies, but tested negative for bee sings. He has asthma and I noticed he was doing a little coughing today, so I had him use his inhaler. After his shower this evening, the area where he was stung, is red and a little swollen. Should I be concerned as this was the first time he was ever stung? He's not having any breathing issues or I'd already be at the ER. Thank you.