The red, itchy and hard lumps on the skin after insect bites belong to insect bite dermatitis, which can be treated by life adjustment, topical medication and oral medication. 1. Life adjustment: patients in daily life, should keep indoor ventilation, in addition to mosquitoes. Avoid using dirty hands to scratch the affected area to avoid triggering local infection. Avoid staying for a long time in places with more mosquitoes. 2. Topical medication: If the symptoms of insect bite dermatitis skin redness, swelling and itching are more serious, you can follow the doctor’s instructions to use glycerite lotion topical application, to play an anti-inflammatory, antipruritic effect, to avoid scratching the local caused by infection. 3. Oral medication: insect bite dermatitis due to insect saliva and venom will invade the skin, the patient may appear red, swollen, itchy skin, hard lumps with itching allergy symptoms. Patients can follow the doctor’s instructions to take antihistamines, such as loratadine, cetirizine and so on. If the skin appears red, swollen, itchy and hard lumps after being bitten by the bugs, it is recommended to go to a regular hospital and be treated under the guidance of a doctor.