A 63-year-old Ecuadorian male patient with a history of type 2 diabetes mellitus (T2DM) and adult-onset Still's disease (AOSD) was admitted to a local hospital for presenting chronic fever and fatigue. AOSD was diagnosed approximately 3 years ago and treated with 2 cycles of Etanercept, oral corticosteroids, and methotrexate. His symptoms were attributed to the usage of monoclonal antibodies. However, after completing the treatment, his condition continues to decline with persistent daily fevers.
On clinical examination, the patient presented Cushing's like fascia ("moon face") and subdermal nodules in the left hypochondrium and left forearm. A chest computed tomography (CT) scan revealed consolidation in the right lung vertex (Figure 1).
Based on the patient's immunosuppression history, tuberculosis was initially suspected, but all test results were negative, including the sputum culture.
Subsequently, a fiber bronchoscopy was performed with negative results, and the patient was started on a course of Piperacillin/tazobactam and quinolone. During hospitalization, the patient became lethargic and within less than 24 h he presented left-sided hemiparesis. The neurology department was consulted to assess for a cerebrovascular accident (CVA). The brain CT scan showed hypodense lesions at the level of the anterior limb of the internal capsule and right lenticular nucleus. A magnetic resonance imaging (MRI) of the brain revealed rounded lesions at basal ganglia and bilateral subcortical cortical lesions in the frontal, parietal, and temporal lobes with bilateral cerebellar lesions of different sizes on T2-weighted imaging (T2-WI) and Fluid-attenuated inversion recovery-weighted imaging (FLAIR-WI) (Figure 2). Based on the imaging findings, the diagnostic was leaning toward infection of the central nervous system or brain metastasis.
His condition continued to decline to a state of stupor and was admitted to ICU. The patient was sedated and put on ventilatory support. Cerebrospinal fluid (CSF) reported adenosine deaminase (ADA): 11 UI/L, proteins: 110 g/dl, glucose: 82 mg/dL, Lactate Dehydrogenase (LDH): 35 U/L, negative liquid cultures, no growth in Chinese ink culture, C-reactive protein (CRP): negative for TB.
In collaboration with the infectious diseases department, the patient received antituberculous drugs plus a course of broad-spectrum antibiotics. A control brain CT scan revealed an increase in size and number of the aforementioned lesions. Brain MRI with spectroscopy showed a peak of choline that confirmed neuro infection (Figure 3). Despite the treatment, fever persisted, and symptoms were not improving. After consulting the neurosurgery department, a CT-assisted stereotactic brain biopsy of the lesions was obtained with no apparent complications, and samples were analyzed with Kinyoun stain confirming the presence of filamentous gram-positive bacillus compatible with Nocardia (Figure 4). Molecular Biology study: Sanger method Sequencing of the 16 S rRNA gene confirmed 99.83% of Nocardia asiatica. Based on these results, a change in antibiotic treatment with trimethoprim/sulfamethoxazole (TMP-SMX) was decided upon. The patient presented partial improvement; however, further complications consequent to paralytic ileus led to multi-organ failure, and death.