Role of Enterobius vermicularis in the aetiology of appendicitis.

An evaluation was made of the histological material obtained from all 1529 appendices removed during the last 5 years at Southmead Hospital, Bristol, in order to elucidate possible relationships between the incidence of Enterobius vermicularis and the origin of inflammation in the appendix. In total, 1419 appendices were removed as cases of clinical appendicitis and 110 in the course of another surgical procedure. E. vermicularis was identified in 2.7 per cent of patients with clinical appendicitis and was most commonly seen in appendices with either chronic inflammation or where the appendix was histologically normal. E. vermicularis was rarely associated with histological changes of acute appendicitis. No cases of E. vermicularis infestation occurred in appendices removed during the course of other surgical procedures. The results suggest that, although E. vermicularis may have a causal role in appendicular pain and chronic inflammation, it is rarely related to acute appendicitis.