Acute appendicitis complicated with necrotizing fasciitis in a patient with adult-onset Still's disease A case report

Rationale: Adult-onset Still disease (AOSD) is a rare systemic inflammatory disease of unknown etiology characterized by evanescent salmon-pink rash, spiking fever, arthralgia/arthritis, and lymphadenopathy. AOSD sometimes was fatal when it is complicated by macrophage activation syndrome (MAS) or hemophagocytic lymphohistiocytosis (HLH). Nonetheless, the literature provides no recommendations for treatment of AOSD patients with severe sepsis. Patient concerns: A previously healthy 65-year-old man with history of AOSD was referred to our hospital for persistent right lower quadrant abdominal pain for 2 days. One week later, an abdominal wall abscess and hematoma developed by extravasation from the inferior epigastric vessels, complicated by necrotizing fasciitis of the right thigh and groin region. To our best knowledge, this case was the first reported case of a perforated appendix complicated with necrotizing fasciitis in a patient with AOSD. Diagnoses: The patient was diagnosed as acute appendicitis complicated with necrotizing fasciitis and abdominal wall abscess. Interventions: This case received intravenous tigecycline injection and daily 10mg prednisolone initially, and shifted to daily intravenous hydrocortisone 200mg for suspected MAS or HLH. This patient underwent surgical intervention and debridement for necrotizing fasciitis. Outcomes: The patient's symptoms progressed worse rapidly. He died from cytomegalovirus viremia and bacterial necrotizing fasciitis complicated by septic shock. Lessons: (1) The steroid dose was difficult to titrate when AOSD complicated by sepsis. The differential diagnosis from MAS/HLH with bacterial/viral infection related severe sepsis was difficult but critical for decision making from clinicians and rheumatologists. (2) The conservative treatment with antibiotics for perforated appendix is safe but has a higher failure rate in immunocomprised patients such as systemic lupus erythematosus and AOSD. Early surgical intervention might contribute to better outcome. (3) The abdominal wall abscess can be spread from intra-abdominal lesion through the inferior epigastric vessels which were as weak points of abdominal wall. Imaging examinations contribute to acute diagnosis and help surgeons perform surgical interventions to prevent morbidity and mortality.