Localized redness and swelling of the skin after the baby’s vaccination is mostly seen as an adverse reaction to the vaccine. Redness and swelling are also common with Pepcid injection, and warm water can be used to apply hot compresses on the redness and swelling to promote the absorption of redness and swelling, for about 20 minutes each time, 4-5 times a day, with good results. If accompanied by fever, local redness and swelling is obvious, there is pus secretion, do not rule out subcutaneous infection or cellulitis after vaccination, need to go to the regular hospital surgical clinic as soon as possible, give local treatment, so as not to cause adverse reactions and other complications of the baby.