What Is The Treatment For A Pimple In The Lip?

SIR,MY SON HAS A SMALL PIMPLE ON THE LIP.THEN THE WHOLE LIP IS BURNT.WHEN WE CONSULT THE DOCTOR ,THE DOCTOR SAID IT IS A DRUG INFECTION.AND GOT THE TREATMENT OF DRUG INFECTION.THE DOCTOR GIVE HIM A INJECTION OF TEXIM & DEXONA.WHEN THE INJECTION IS STOPPED,THE ANTI BODY REACTION IS AGAIN SEEN IN THE BODY.THE DOCTOR ALSO GIVE THE MEDICINE OF ZYRTEC SYRUP AND WYSOLONE TABLET. BUT THE ANTIBODY REACTION IS NOT GONE.AGAIN WE WENT TO THE DOCTOR AND NOW THE DOCTOR SAID IT IS HARPIES .IT CAN BE CURED IN 10 DAYS.WHAT IS THE BEST TREATEMENT FOR MY CHILD.AND WHAT IS THE PRECAUTIONS SHOULD BE TAKEN.I AM VERY GLAD IF YOU RECOMMEND THE BEST TREATEMENT AS I AM IN PROBLEM FOR LAST 1.5 MONTHS.