Hi..
Welcome to HEALTHCARE MAGIC.
As per your complain if you have pus coming out of the extraction site then there is a strong possibility that the socket has not healed completely yet and there is infection leading to pus discharge..
There is also a possibility that there is any left over root piece in the socket that is flaring up the infection and causing pus formation..
As far as
rash over the skin of the jaw is concerned it can be due to
allergic reaction to any medication that you might be taking post extraction..
If not it can be due to allergic reaction to any food or skin cosmetic while can also be due to staphyloccous bacteria infection..
You should consult your
dentist and get evaluated and a thorough clinical evaluation and investigations like
x ray will help in ruling out the exact cause of the pus discharge..
If there is infection then a course of antibiotics along with irrigating the socket with antiseptic solution and warm saline gargles will help..
If there is any left over root piece, removing the same will help..
For the rash as of now take Levocetrizine and do cool compresses but if not resolved consult a General Physician or a
Dermatologist..
Hope this helps..
Regards.