Introduction

Enterobius vermicularis, also known as pinworm or threadworm, is a common intestinal parasite, particularly in children.Approximately 12.9% of children around the world have been infected withE. vermicularis [1]. The World Health Organization reported that the prevalence of enterobiasis in children is between 4% and 28%. [2].Some patients with enterobiasis are asymptomatic, while others, especially children, may show symptoms such as perianal pruritus, restlessness, loss of appetite, malnutrition, anemia, insomnia, and irritability. Sometimes,enterobiasis can affect the kidneys and fallopian tubes, leading to severe health disorders and even death. [3] [4].

There are multiple ways to transmit enterobiasis, including the faecal-oral route, inhalation, auto-infection, and retrograde infection [5]. The main route of transmission forE. vermicularisis direct contact between infected and uninfected individuals. Therefore, children in crowded environments such as kindergartens, schools, orphanages, and mental institutions are most susceptible to this infection [6].

Case presentation

A 23-year-old male with no significant past medical or surgical history presented to the emergency department at Raipur Institute of Medical Sciences, complaining of right iliac fossa abdominal pain of a one-week duration. The pain was progressive with associated anorexia. He denied any history of fever or change in his bowel habits. On examination, his vital signs were within normal limits. His abdominal examination revealed tenderness in the right iliac fossa with a positive rebound sign. Urine analysis showed that no infection was present. Laboratory investigations showed a hemoglobin level of 13.3 g/dL, a white cellcount of 4100, and a C-reactive protein level of >4.0 mg/L (raised). The coagulation profile, Liver function test, and renal function tests were normal.

The patient’s pelvic ultrasonography showed a blind ended non peristaltic tubular structure (measuring 11.2 mm in diameter) with a thickened wall. A mild patchy increase in mural vascularity and adjoining patchy minimal free fluid is noted in the RIF region. A computed tomography (CT) scan was performed, given the low probability of acute appendicitis,

Figure 3: H&E stain, appendix mucosa on a 10 X view showing ulcerated epithelium with inflammatory infiltrate and intraluminal Enterobius vermicularis eggs.

Figure 4: H&E stain , appendiceal wall a 40 X magnification, showing evidence of E. vermicularis infection in the form of E. vermicularis eggs.

Discussion

The pathogenesis of acute appendicitis is mainly due to luminal obstruction, with various causes including lymphoid hyperplasia in children, faecoliths, tumors, and helminths, etc. All of these can increase intraluminal pressure and compromise mucosal blood supply, which can lead to hypoxia or ischaemia of the tissue. This later on promotes several microbial invasions of the appendiceal wall, which lead to acute appendicitis. Diagnosis mainly relies on specific clinical presentation—characterized by right lower abdominal pain, nausea, vomiting, and anorexia—along with laboratory findings such as leukocytosis, as well as imaging techniques like ultrasound. Several parasites have been reported as the cause of acute appendicitis. Altun E, Avci V, and Azatcam M carried out a retrospective analysis of 660 patients and a brief literature review that shows Enterobius and Taenia as the main causes of acute appendicitis. [7]. One study shows that Ascaris lumbricoides can cause appendicitis,