Swollen bags of hard lumps after being bitten by mosquitoes and insects are mostly considered to be insect bite dermatitis, which can be improved by topical and oral medication and daily care. 1. medication: if the patient was bitten by mosquitoes, there is a large swollen hard lumps. Topical glucocorticosteroids such as hydrocortisone, dexamethasone, tretinoin, etc. can be used under the guidance of a doctor. When the itching is significant, oral antihistamines such as loratadine citrate and levocetirizine hydrochloride can be taken. For severe insect bite dermatitis, the need for systematic use of glucocorticoid drug therapy, oral prednisone can be used in small doses to control symptoms. 2. Daily care: patients should avoid scratching the lesions, keep the skin clean. Daily should do a good job to prevent mosquito bites, you can choose to apply mosquito repellent products, when you go out can wear long clothes and long pants. When the mosquito bites, there are swollen bags of hard lumps, you can go to the hospital, under the guidance of the doctor with medication.