The piriformis abscess: a case-based review

Mohammadreza Salehi; Fereshteh Ghiasvand; Mohammad Mehdi Feizabadi; Mohammad Zarei; Niloofar Ayoobi Yazdi; Neda Alijani; Mehdi Qaempanah; Simin Seyedpour

doi:10.18502/ijm.v13i2.5988

Mohammadreza Salehi Department of Infectious Diseases, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
Fereshteh Ghiasvand Department of Infectious Diseases and Liver Transplantation Research Center, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
Mohammad Mehdi Feizabadi Department of Microbiology, School of Medicine, Thoracic Research Center, Imam Khomeini Hospital Complex, Tehran University of Medical, Tehran, Iran
Mohammad Zarei Joint Reconstruction Research Center, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
Niloofar Ayoobi Yazdi Department of Radiology, School of Medicine, Advanced Diagnostic and Interventional Radiology Research Center, Tehran University of Medical Sciences, Tehran, Iran
Neda Alijani Department of Infectious Diseases, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran 7Department of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Mehdi Qaempanah Department of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Simin Seyedpour Department of Medicine, Tehran University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/ijm.v13i2.5988

Keywords: Bacterial infection; Abscess; Staphylococcal infections; Piriformis muscle syndrome; Pelvic pain

Abstract

This study reports a 43 years-old man diagnosed with piriformis pyomyositis. A literature review was conducted by searching MEDLINE via Pubmed for English language case reports, published from 8 th December 2019 to 20th January 2020. Patients' symptoms, laboratory tests, imaging, treatment, and other comorbidities were evaluated. Thirty-two cases diagnosed with piriformis pyomyositis, of which 21 patients developed piriformis abscess (including one new patient added by us) of which 52.4% were female, and the mean age was 26.98 ± 17.5. The most common manifestations were fever, lower back pain, and limited ambulation with increased ESR, CRP, or leukocytosis. Staphylococcus aureus was the most prevalent (57.14%) pathogen isolated. The authors suggested gynecologic manipulations, muscle overuse, and other co-infections as probable risk factors. However, we fail to find any association between these factors and abscess formation (p>0.05). Piriformis abscess should be regarded as a probable diagnosis in patients with gluteal pain, fever, and limited ambulation that have raised inflammatory markers or leukocytosis. MRI and CT scans are beneficial in diagnosing pyomyositis in early-stage. Full recovery is expected with timely antibiotic and surgical treatments.