The swollen, hard and itchy area on a child’s foot bitten by an insect is insect bite dermatitis, which can be improved by general treatment and medication. 1. General treatment: when parents find children’s feet by insect bites, available flowing water or soapy water cleaning to reduce the toxic substances on the local tissue caused by irritation. For swelling, itching phenomenon, parents can also use dry towels wrapped in ice packs local ice packs, which helps to constrict blood vessels, relieve discomfort. 2. medication: parents can follow the doctor’s instructions for external glycerine lotion, or dexamethasone, hydrocortisone and other glucocorticoid therapy, in order to achieve astringent, anti-itching, anti-inflammatory effect. For itching symptoms can be oral cetirizine, loratadine and other antihistamines to improve. Parents are advised to give medication to their children under the guidance of a doctor, and not to use drugs or prescriptions on their own.