An enemy in shadows—Mycoplasma hominis septic arthritis and iliopsoas abscess: Case report and review of the literature

•The pathogenic potential of Mycoplasma hominis.•The diagnostic challenges of M. hominis extragenital infections.•M. hominis septic arthritis, particularly in immunocompromised hosts needs to be considered.•Molecular methods have revolutionized the detection of M. hominis and can prevent devastating consequences.•Prolonged antibiotic therapy targeting M. hominis in addition to appropriate surgical interventions is the mainstay of management. Mycoplasma hominis (M. hominis) is fastidious and difficult to grow bacteria with the ability to colonize the genitourinary and respiratory tracts. Infrequently can cause a variety of genitourinary tract infections, pregnancy complications, and neonatal diseases. M. hominis rarely reported to cause extragenital infections and seldomly native joint septic arthritis particularly in immunocompromised hosts, raising diagnostic challenges and is often associated with delayed diagnosis and high morbidity and mortality. We report the case of a 30-year-old patient who developed M. hominis native left hip septic arthritis with iliopsoas abscess after receiving rituximab for newly diagnosed thrombotic thrombocytopenic purpura (TTP). The diagnosis of M. hominis hip septic arthritis with iliopsoas involvement was confirmed following repeated joint and abscess aspiration and identification of the organism with the aid of culture and specific Polymerase chain reaction (PCR). The patient was subsequently treated with a prolonged course of antibiotics targeting the organism with a favorable outcome. The clinical presentations, assessment, and management of this rare entity of M. hominis related extragenital infections are outlined. In addition, the literature on similar cases was reviewed to raise awareness and avoid devastating consequences.