Talk to General Physician on Skin Infection

My mother had severe headache some days back and injected Voren (high dose) by a general physician. After that it swelled alot with hardness and it is becoming worst day by day. Now what are the possible treatment methods? She is taking medicines from past 3 days but there is no difference in swelling. As one of the doctor said that it needs a minor surgery for cleaning the infected area. She is tripanophobic. Can any specific medicine treat it completely or the surgery is the last option? Please guide!