Life-threatening MRSA sepsis with bilateral pneumonia, osteomyelitis, and septic arthritis of the knee in a previously healthy 13-year-old boy: a case report

Abstract

The incidence and severity of methicillin resistant Staphylococcus aureus (MRSA) infections are increasing and cause high mortality and morbidity. We describe the first pediatric case in Scandinavia with Panton-Valentine leucocidin (PVL) positive MRSA septicemia who developed bilateral pneumonia, arthritis of the knee, and osteomyelitis of the tibia. Radiological investigation and interpretation directed the treatment, especially the surgical debridement, and combined with clinical and biochemical findings lead to close interdisciplinary treatment with frequent surgical interventions and antimicrobial combination therapy. The outcome was a healthy patient without sequelae, a favorable course unlike those previously described in the literature. This case underlines the necessity of a close interdisciplinary cooperation in children with severe MRSA infection encompassing pneumonia, septic arthritis, and osteomyelitis, using different imaging modalities to guide the surgical and antibiotic treatment.

Keywords: MRSA; arthritis; child; osteomyelitis; septic.

Fig. 1.

(a) Initial MRI, coronal T1 (left image) and axial proton fat-saturated images of the knee show irregular bone marrow signal intensity in the tibial metaphysis consistent with edematous changes (arrow on left-sided image) in addition to intraarticular fluid collection (black arrow on right-sided image) and fluid collection in the surrounding soft tissue (white arrows). (b, c) Supplementary STIR (left images) and post-contrast T1 fat-saturated images, coronal slice of the whole leg (b) and axial slices (c) corresponding to the metaphysis show a not enhancing fluid collection subperiostally (white arrows) compatible with abscess formation in addition to pronounced soft tissue edema and a small not enhancing soft tissue collection (black arrow on (b)).

Fig. 2.

Chest X-ray shows bilateral pronounced pulmonary infiltrates with accompanying left-sided pleural effusion.

Fig. 3.

(a, b) Osteomyelitis of the tibial diaphysis with abscesses and destruction of the diaphysis.

Fig. 4.

Radiography showing irregular osseous structure in the proximal tibia with a mixture of lytic and sclerotic areas in addition to periosteal new bone formation. Sequestration cannot be excluded.

Fig. 5.

Bone (upper image) and leucocyte scintigraphy show tracer uptake in the entire tibia and no sign of pathological leucocyte accumulation (lower image).

Fig. 6.

X-ray of the left leg 22 months after the initial therapy showing nearly normal conditions.