Pyogenic Sacroiliitis and Pyomyositis in a Patient with Systemic Lupus Erythematous

Abstract

Pyogenic sacroiliitis and pyomyositis are uncommon infectious diseases and their diagnoses are often delayed. They are typically seen in children and young adults and are rare in middle-aged people especially in those affected by rheumatic diseases. We present the first case of a Staphylococcus aureus related pyogenic sacroiliitis associated with iliacus and gluteal pyomyositis occurring in a patient with systemic lupus erythematosus. Antibiotic treatment was administered for a total of 6 weeks with a total recovery. Pyogenic sacroiliitis and pyomyositis, although remaining rare events, should be remembered as severe complications in immunosuppressed patients with inflammatory diseases. Early clinical suspicion, imaging diagnosis, and adequate therapy are decisive for the satisfactory outcome.

Septic arthritis of the sacroiliac joint

“…The most common pathogen which causes septic arthritis (including the sacroiliac joints) is Staphylococcus aureus [ 6 , 11 – 14 ], but there are described cases of other pathogens like Salmonella spp., Brucella spp., Streptococcus pyogenes [ 15 – 18 ].…”

“…Fast diagnosis and the implementation of antibiotic therapy isextremely important in the treatment process for this disease. Not treated septic arthritis leads to serious complications such as sepsis, abscess formation or infection of other organs, including the vegetations on the endoprosthesis [ 10 , 14 , 18 , 19 ].…”

Pyomyositis in a patient with systemic lupus erythaematosus and a review of the literature

“…Of these cases, 13.0% were invasive (n=3),14 18 21 78.3% were suppurative (n=18)4–10 12 13 15 17 19 20 22–25 and 8.7% were late stage PM (n=2) 11 16. At least 47.8% (n=11/23) met the criteria for sepsis,4 5 11 15 16 19 21 22 24 25 and bacteraemia was evident in 7 of 13 documented blood culture results 5 6 16 17 21 22 24…”

“…In certain cases, sciatica,5 deep vein thrombosis,6 fasciitis,7 aseptic necrosis of the femoral head,9 recurrent cellulitis,14 inflammatory myositis,21 or fever with nodular lesions25 is diagnosed prior to a PM diagnosis. In many cases, the invasive stage is prolonged in mycobacterial infections14 21 25 but shortened in non-mycobacterial infections 15–17 22 24. A lupus flare-up, which sometimes precedes or is accompanied by muscle tenderness and requires intense immunosuppressive therapy, can complicate the treatment of PM or even cause death 13.…”

“…At least 34.8% (n=8/23) of published cases showed evidence of lupus flares as hypocomplementaemia or elevated anti-double-stranded DNA antibodies. At least 30.4% (n=7/23) of the blood cultures were positive (compared with 20–30% in temperate regions)2 and, in one case, pathogenic bacteria were diagnosed based on blood culture alone 24. For cellulitis in immunocompromised hosts, blood cultures should be obtained to assess PM 28…”