Abstract
BACKGROUND: Septic arthritis of the sacroiliac joint is an uncommon condition, accounting for only 1-2% of all septic arthritis cases. Its rarity, coupled with a nonspecific clinical presentation, often leads to diagnostic delays. While Staphylococcus aureus is the most common pathogen, Salmonella species are rare etiological agents, typically associated with specific risk factors. This case highlights the novelty of a Salmonella enteritidis-induced septic sacroiliitis in a previously healthy adolescent of Ladino ethnicity, emphasizing the importance of considering atypical pathogens. CASE PRESENTATION: A 17-year-old Ladino male presented with severe lower back and buttock pain radiating to the left leg, 1 week after recovering from a gastrointestinal illness. Laboratory findings revealed elevated inflammatory markers, and imaging showed significant inflammation of the left sacroiliac joint. Diagnosis was confirmed via joint fluid aspiration, which identified S. enteritidis. The patient was treated with intravenous ceftriaxone and amikacin, transitioning to oral antibiotics for 6 weeks. Symptoms resolved within 72 hours of treatment initiation, with full recovery of mobility and sustained symptom-free status at 1-year follow-up. CONCLUSION: This case underscores the importance of timely diagnosis and tailored treatment for septic sacroiliitis caused by atypical pathogens. It also highlights the need to consider Salmonella in patients presenting with sacroiliac joint pain and a recent history of gastrointestinal infection, even in the absence of traditional risk factors, ensuring optimal clinical outcomes.