The case study of chronic nonbacterial osteomyelitis with lung involvement and development of cerebral abscess Dietzia sp. etiology

We report a case of a 3.5-year-old girl, who had recurrent episodes of fever, migratory joint pain and swelling, disseminated papulopustular rash for the first time in December 2018. The girl was born from physiological pregnancy, had no family history of rheumatological, autoimmune diseases or consanguinity.  In February 2019 there was osteomyelitis at the junction of os pubis and os ischii in MRI, WBC 22.7x10^3/uL; CRP 56.0 mg/L. Blood culture remained negative. With antibiotics the imaging changes, laboratory markers and symptoms normalized. In March she had headache, rhinitis, rash and limping, but no changes in joint examination. A cranial CT scan revealed pansinusitis. During antimicrobial treatment the symptoms disappeared. In May-June fever, rash and swelling on the left side of the face were observed. MRI showed chronic mandibular osteomyelitis, leading to suspicion of CNO. A jawbone biopsy showed fibrous dysplasia. Naproxen was initiated. In September, MRI of the mandible showed progression of changes. Repeated examination of biopsy sent to Helsinki and radiological images sent to Tartu were consistent with the CNO diagnosis. Cultures remained sterile. In October PET/CT showed hypermetabolic foci in both lungs, left mandibula, left proximal tibia and distal metaphysis of femur. A lung biopsy revealed non-necrotizing granulomatous inflammation. Tbc, immunodeficiency with granulomatosis, secondary sarcoid-like reactions and lung infections were excluded. After vast investigations in February 2020 methotrexate, etanercept and pamidronate were initiated. Due to lung changes the patient received azithromycin. After treatment initiation, she started experiencing episodic vomiting. In May MRI revealed pansinusitis and cerebral abscess in the frontal lobe without purulent signal. Supraorbital craniotomy, intracranial abscess resection and maxillotomy were performed. Granulomatous tissue found was sent for histological, bacteriological and fungal examination. Gram-positive bacteria growth (Dietzia sp.) was found and long-lasting antibacterial treatment was started with clinical and radiological imaging improvement.