Infants with many small red bumps on the neck if caused by mosquito bites, generally can be relieved by itself, caused by prickly heat can use prickly heat powder, caused by eczema can use glucocorticoids. 1. Mosquito bites: mosquito bites can cause the phenomenon of red bumps, usually can recover by themselves. 2. Prickly heat: summer is prone to the phenomenon of prickly heat on the neck, usually should pay attention to keep the skin dry and clean, can be appropriate to use baby prickly heat powder to relieve. 3. Eczema: Red bumps can be caused by eczema, which can be treated with glucocorticoids such as hydrocortisone. If the red bumps on the neck of the baby is obvious, go to the hospital for examination, the use of the above drugs should follow the doctor’s instructions.