Mosquito bites are swollen the next day is considered to be insect bite dermatitis, the need for local drug therapy, oral medication, and strengthen the care. 1. Local medication: you can use local boric acid solution, potassium permanganate solution, etc. for wet compresses, for accompanied by strong itching can be coated with medium-acting or strong glucocorticoid ointment, such as dexamethasone dipropionate, Haxinaid, etc.. 2. Oral medication: If the itching is intense, you can take oral antihistamine medication, such as ibastine, loratadine, etc. If there is a rupture due to scratching, you should also use antibiotic medication to prevent infection, such as cefuroxime, roxithromycin and so on. 3. Enhanced care: most patients will have symptoms such as redness, swelling and itching after being bitten by mosquitoes, but a small number of patients will have delayed allergic reaction, that is, there is no reaction on the same day and symptoms appear on the next day, and a very small number of patients will have a systemic reaction, with respiratory difficulties and dizziness, etc., which should be observed at any time. If there is no significant recovery after simple treatment and accompanied by systemic symptoms, seek medical attention as soon as possible. If medication is needed, it should be strictly followed.