Acute Pyogenic Osteomyelitis of the Pubic Bone in a Patient with Systemic Lupus Erythematosus Mimicking Fracture of the Pubic Bone and Periprosthetic Joint Infection of the Hip

Abstract

Introduction. Pubic bone osteomyelitis is atypical, and the diagnosis is often overlooked. It may present as osteitis pubis, fracture, or noninfectious inflammation of the pubic symphysis. Case Report. We report a case of a 65-year-old lady who has systemic lupus erythematosus with acute pyogenic osteomyelitis of the pubic bone who presented initially with a suspicious healing pubic rami fracture and periprosthetic infection of the hip joint. Conclusion. Acute osteomyelitis of the pubic bone has often an infrequent and delayed presentation. Clinical awareness, early diagnosis, and appropriate treatment including surgical debridement and long-term antibiotics can prevent ongoing morbidities such as chronic osteomyelitis, pain, and deformities of pelvic bone and joints.

Bone Involvement in Systemic Lupus Erythematosus

“…Infections strongly affect morbidity and mortality in SLE [ 57 , 59 ]. Herrinton et al reported a six- to seven-fold greater risk of serious infection than the general population [ 60 ], mainly due to impaired function of immune system and immunosuppressive treatment [ 59 , 61 ]. Infections may be life-threatening and represent one of the leading causes of death in SLE [ 60 , 62 , 63 ], accounting for 25% to 50% of overall mortality [ 63 ].…”

“…OM is more frequent in SLE patients than in the general population [ 57 , 59 ], moreover occurring at a younger age [ 57 ]. Several studies and case reports described OM in SLE, due to different microorganisms [ 50 , 59 , 61 , 67 , 68 , 69 , 70 ] and affecting mainly bones of the lower limbs, in particular tibia and femur [ 57 , 59 ].…”

“…Different conditions may be associated with higher risk of OM development in SLE, particularly impaired immune system, GCs and immunosuppressive treatment, high disease activity, underlying bone and joint pathology such as bone infarcts or prior bone fracture, old age (>60 years) and pediatric age, male gender, and malignancy [ 59 , 61 , 63 , 67 , 68 , 69 , 70 ].…”

“…GCs predisposing OM may be related to dose and duration of treatment [ 59 , 61 , 63 ]. As reported by Huang, a prednisone equivalent dose of more than 7.5 mg for more than 180 days was associated with increased risk of major infection and OM in SLE [ 59 ].…”

“…As reported by Huang, a prednisone equivalent dose of more than 7.5 mg for more than 180 days was associated with increased risk of major infection and OM in SLE [ 59 ]. Thus, GCs may increase the risk of opportunistic infections, including OM [ 59 , 61 ]. Immunosuppressive treatment may contribute to increased risk of infection and OM [ 59 ]; among immunosuppressive drugs, cyclophosphamide could deeply reduce immune system function, inducing leukopenia [ 63 ].…”