Hi welcome to Health care magic forum. It is an abscess
formed as sebacious cyst
, as it ruptures little pus oozes out, leaving behind the pus pocket, which is to be liquified and come out. For that medicines are to be used under the supervision of a doctor. Surgeon is the doctor concerned but no problem who ever it may be.
Besides i advise you some diet recommendations as avoid taking pulses, potato , other tubers, and fish.
Take more of green leafy vegetables, milk, meat, fruits, juices, and dry fruits, to improve blood, general health, resistance to such infections. Wishing for a quick recovery and thanks for calling.