The hard lumps left after the bite of poisonous mosquitoes, i.e., insect bite dermatitis, can be treated by daily care, cold compresses, medication and other methods. 1. daily care: should be timely to improve the living environment, can be used in the space where the mosquito repellent products, not to scratch the affected area, wearing loose and comfortable clothes, avoid friction on the affected area, so as to avoid breakage secondary infection, resulting in aggravation of the condition, not conducive to the recovery of the condition. 2. cold compresses: you can choose to use cold towels, ice packs and other cold compresses on the hard lumps, to a certain extent, can promote the swelling of the hard lumps. 3. Drugs: you can use glycerine lotion to clean the affected area, if the symptoms are serious, you can apply compound dexamethasone cream, mometasone furoate ointment and other drugs, infection can choose to use fusidic acid cream, mupirocin ointment and so on. It is recommended to standardize the use of drugs under the guidance of a professional physician for treatment, not unauthorized use of medication, to avoid the impact on the health of the body.