Psoas primary abscess: A case report in an immunocompetent subject

Primary psoas abscess is a rare disease characterised by a purulent collection in the thickness of the psoas muscle. Its incidence and etiopathogenesis are not well defined. It is mainly encountered in developing countries in weakened conditions. The involvement of an immunocompetent subject is exceptional. We report a case of primary psoas abscess in an immunocompetent patient in Togo. A 67-year-old retired teacher with no previous medical history was seen in the emergency room with acute and severe abdominal pain. The clinical examination revealed an infectious syndrome and a painful abdominal mass in the right iliac fossa. CT scan showed a heterogeneous fluid collection in the right psoas muscle. Surgical drainage was indicated and performed. The patient was treated postoperatively with dual antibiotics with a favourable outcome. No germs were isolated from the collection. Rare infectious disease, its real incidence is unknown. The most common germ is staphylococcus aureus. Its etiopathogenesis is also poorly understood. Immune deficiency is a predisposing factor for the condition. Diagnosis of the disease is difficult due to a lack of specificity of the signs encountered. Imaging is the key to positive diagnosis with a high sensitivity of CT scan. Treatment is medical-surgical with drainage and antibiotic therapy. Primary psoas abscess is a potentially serious disease requiring early diagnosis and management. •Primary psoas abscess is a rare disease of unknown incidence.•It is exceptionally encountered in an immunocompetent subject.•Its diagnosis is difficult because of the lack of specificity of its signs.•The disease is associated with morbidity and mortality and therefore requires rapid and appropriate treatment.•The treatment is medical and surgical, combining antibiotic therapy and drainage of the collection.