Swollen and itchy bites from flying insects are usually insect bite dermatitis, which can be relieved by using topical antipruritics with glucocorticoid ointment and oral antihistamines. If redness, swelling and itching occur after being bitten by flying insects, you can use topical antipruritic agents such as glycerite lotion and glucocorticosteroids such as hydrocortisone cream for relief. You can also take oral antihistamines, including loratadine tablets, cetirizine tablets, ebastine tablets, etc. to relieve allergic symptoms. Avoid scratching and irritation with your hands as much as possible. If the skin symptoms after being bitten by flying insects are serious, you should go to the hospital in time, and the above drugs should be used according to the doctor’s instructions.