Systemic sclerosis (SSc) is an autoimmune (AI) connective tissue disorder characterized by skin fibrosis, vasculopathy and dysimmunity. Data regarding osteitis in SSc are scarce.
We performed a nationwide multicentre retrospective case-control study including patients with SSc according to the 2013 ACR/EULAR classification, with a diagnosis of osteitis. The objectives of the study were to describe, to characterize, and to identify associated factors for osteitis in patients with SSc.
Forty-eight patients were included. Twenty-six patients (54.1%) had osteitis beneath digital tip ulcers. Physical symptoms included: pain (36/48, 75%), erythema (35/48, 73%), and local warmth (35/48, 73%). Thirty-one (65%) patients had C-reactive protein levels >2 mg/L (8 [2.7 - 44.3] mg/L). On X-ray, CT-scans or MRI, osteitis was characterized by swelling or abscess of soft tissues with acro-osteolysis or lysis in 28 patients (58%). Microbiological sampling was performed in 45 (94%) patients. Most pathogens were Staphylococcus aureus (43.8%); anaerobes and Enterobacteriaceae (29.1%) and Pseudomonas aeruginosa (10.4%). Management comprised antibiotics in 37 (77.1%) patients and/or surgery in 26 (54.2%). Fluoroquinolones were used in 22 (45.8%) patients and amoxicillin + beta-lactamase inhibitor in 7 (14.6%). Six (12.6%) patients relapsed, 6 (12.6%) patients had osteitis recurrence, 15 (32%) sequelae, and 2 patients had septic shock and died.
This study confirmed digital tip ulcers as an associated factor for osteitis, and revealed a high rate of functional sequelae. Antimicrobial therapy with oral fluoroquinolone or intravenous amoxicillin and beta-lactamase inhibitor are used as first-line antibiotherapy in SSc patients with osteitis.