P100 Acute crystal arthritis: a leading cause of hospital admission, yet poorly recognised and mistreated

Abstract

Abstract Background/Aims Crystal arthritis is the commonest inflammatory arthritis in adults. A common mimic is septic arthritis. Without appropriate synovial fluid analysis, a mis-diagnosis of sepsis can be made with resultant unnecessary hospitalization, inappropriate intravenous antibiotic therapy and excess cost. Such cases are frequently described as ‘culture-negative’ septic arthritis. We aimed to examine and analyse the cases of acute arthritis requiring acute hospital admission in a tertiary referral centre in Dublin. Methods A retrospective review of database between Jan - Dec 2019 at the Mater Misericordiae University Hospital, Dublin, was carried out. All cases of acute arthritis requiring acute hospital admission were identified. Cases treated at the Emergency Department, Acute Medical Unit or Outpatients which did not require hospital admission were excluded. Results 30 patients were identified during this period, 16 (53%) had an ultimate diagnosis of crystal arthritis, 8 (27%) had confirmed septic arthritis and 6 (20%) had other arthritides (e.g. haemoarthrosis). The median age for crystal arthritis was significantly higher (85.5 y) compared to septic arthritis (47 y). Apart from age, the clinical profile and biomarkers for crystal and septic arthritis were comparable. The majority of crystal arthritis cases were due to pseudogout (69 %), ultimately diagnosed by rheumatology. Septic arthritis led to more days in hospital than crystal arthritis (median 14 vs 5.5 days). All 30 patients received IV antimicrobial therapy for presumed septic arthritis. Conclusion This retrospective study showed crystal arthritis, especially pseudogout, was the commonest cause of hospital admission (53%) with acute arthritis particularly among elderly patients. Accurate diagnosis by synovial fluid analysis with appropriate equipment is extremely useful in the assessment of these cases. More awareness and training among orthopedic, emergency and acute clinicians is needed in order to avoid unnecessary admissions and interventions. Disclosure A. Abdalla: None.