# “Iliacus muscle abscess as an unexpected cause of posterior hip pain in a healthy young adult female”: a case report

## TL;DR

A young woman's hip pain and fever were caused by an unusual muscle abscess, highlighting the need for careful diagnosis.

## Contribution

This case report presents an atypical iliopsoas abscess mimicking respiratory and musculoskeletal issues in a young, healthy patient.

## Key findings

- Elevated CRP levels prompted imaging that revealed an iliopsoas abscess in a patient with no typical risk factors.
- CT-guided aspiration and targeted antibiotics successfully treated the abscess and resolved symptoms.

## Abstract

Iliacus muscle abscess is an uncommon but potentially life-threatening condition that can present with nonspecific symptoms, posing diagnostic challenges. This case report highlights the importance of considering iliopsoas abscess in patients presenting with fever and hip pain, especially in the absence of obvious risk factors or penetrating trauma. The novelty of this case lies in its atypical presentation mimicking a respiratory viral infection and musculoskeletal injury, impeding accurate diagnosis and appropriate management.

A previously healthy 21-year-old female who had a mechanical fall 3 weeks prior presented with fever, right hip pain, and respiratory symptoms, initially suggestive of a respiratory infection and musculoskeletal injury. However, initial investigations revealing a markedly high C-reactive protein (CRP) concentration prompted further computed tomography (CT) imaging of her abdomen and pelvis, which uncovered an iliopsoas abscess presumably stemming from antecedent trauma. Subsequent CT guided aspiration along with culture-sensitive antibiotics led to successful treatment and resolution of her symptoms.

This case emphasizes the importance of considering iliopsoas abscess as a possible differential, even in young patients without typical risk factors. Markedly elevated inflammatory markers such as CRP concentrations can serve as a vital indicator, directing attention towards the possibility of septicemia or the presence of an occult abscess, facilitating prompt imaging and accurate diagnosis.