12 Simultaneous appendicitis and perianal abscess: the importance of an adequate medical history in the Emergency Department
Authors: Moret Rebeca Abad , Suárez Enríquez Ana Belén , Vera Blanca Monje , Gómez Luis Asensio , Rubio-Pérez Inés 
Published: February 2025

Abstract

Introduction
Fever is one of the most common signs in patients presenting to the Emergency Department, and usually translates to an underlying infectious process. When taking a patient’s medical history, it is essential to record all signs and symptoms to orientate the diagnosis. All potential sources of infection must be systematically evaluated to avoid errors or diagnostic oversights. Although uncommon, a patient may present with 2 different simultaneous infections that need surgical intervention, as in the case presented.

Case Report
We present the case of a 76-year-old woman with a history of HTA, Factor V Leyden, chronic low back pain, diverticulosis, asthma and atrial fibrillation (anticoagulated with Eliquis), who presented to the Emergency Department with fever and a perianal swelling of 3 days’ duration, associated with discomfort in the hypogastrium. On physical examination, she had tenderness on palpation in the hypogastrium without clear signs of peritoneal irritation, and an ischioanal abscess was evident in the perineal examination. Laboratory tests showed leucocytosis and an elevated C-reactive protein (CRP) of 123 mg/l. Despite the straightforward surgical diagnosis of perianal abscess, the abdominal pain and symptoms were suspicious, so an abdomino-pelvic CT scan was requested to complete the study and rule out other conditions. The CT revealed a collection in the left ischioanal fossa, and additionally, an enlarged appendix (1.2 cm) with parietal enhancement, trabeculation of the local fat with reactive lymph nodes, and a small collection adjacent to the tip of the appendix, consistent with acute appendicitis. Urgent surgery was decided. In the same surgical procedure, laparoscopic appendectomy, and exploration under anaesthesia and drainage of the ischioanal abscess were carried out. The patient had a favourable postoperative course, remaining afebrile, tolerating a progressive diet, having normal bowel movements, and undergoing periodic dressing changes in the perianal area. She was discharged on the 3rd postoperative day, completing a 7-day course of amoxicillin-clavulanate antibiotic therapy. In the one-month postoperative follow-up in outpatient clinics, the patient was clinically well, the perianal wound had healed, and the pathological examination confirmed acute appendicitis. She was discharged by the General Surgery team.

Educational Highlights
In the Emergency Department, it is essential to conduct a detailed medical history, paying attention to each symptom reported by patients, as well as conducting a thorough physical examination and complementing the diagnosis with imaging tests when necessary. This is especially important for surgical residents. In this case, fever originated from two potential infection sources, highlighting the need to approach patients comprehensively and use different methods for diagnosis. When the treatment for the infection is surgical, the basic principles of drainage and/or removal of the affected organ must be observed to achieve an adequate source control. In this case, a single intervention resolved both infections. If one of them had been overlooked, there could have been confounding factors in the postoperative course, clinical worsening and even sepsis.