Hello and welcome to healthcare magic.
I am dr asad sami.I have red your question and i can understand your concerns.
Is your child running temperature..?
Are you or your child diabetic.?
Were proper antiseptic measures applied while vaccinating your child..??
From the information you provided it seems that your child has injevtion site
abscess.if i were his treating physician i would have done pus culture and sensitivity and prescribe antibiotics such as
amoxicillin plus clavulunic acid 57mg.i would have incised and drain it if the abscess were mature with loculi.
I would have looked for
haematoma at the injection site which usually subsides with time.
I would suggest you to meet a
pediatrician.In the mean time remain calm and keep that area clean with antiseptics such as dettol or
hydrogen peroxide.
Thanks.
Hope the answer is helpful.
Feel free to ask further questions.
Regards