Bacteriology of Epidermoid Cysts

Abstract

We examined aerobic and anaerobic bateria isolated from 53 inflamed and 22 uninflamed epidermoid cysts between July 1998 and April 2002. The main bacteria were coagulase negative staphylococci and Corynebacterium which were aerobically isolated from both inflamed and uninflamed cysts. Anaerobic bacteria included Peptostreptococcus, Propionibacterium, Veillonella, Prevotella. More Propionibacterium acnes (P. acnes) and gram nagative cocci were anaerobically isolated from inflamed cysts than uninflamed cysts. We could isolate more bacteria from cases that have not received antimicrobial treatment than from those treated before specimens were obtained. However, the bacteria were isolated from most cysts. Treatment or lack of treatment had no influence on whether the cyst was inflamed or uninflamed. The presence of anaerobic flora such as P. acnes and/or some gram nagative cocci may lead to inflamation in some cysts.