Mosquito bites with redness, swelling and hard lumps belong to an allergic reaction called insect bite dermatitis, which requires daily care and medication. 1. Daily care: After being bitten by mosquitoes, it is recommended to wash the affected area with running water and then dry it with a cotton towel to keep the skin clean and dry. Do not scratch with your hands to avoid the redness and swelling of the hard lumps to increase, or even break out and become infected. 2. Medication: After cleaning, glucocorticosteroids such as Dinaid cream and Tretinoin acetate cream can be used for treatment as prescribed by the doctor. If the symptoms are more serious, you can use loratadine tablets, cetirizine hydrochloride tablets, etc. as prescribed by the doctor. Mild symptoms can only daily care, if you need to use drugs, need to use under the guidance of a doctor.