Disseminated

Background: Nocardiosis is an opportunistic infection caused by aerobic, Gram-positive actinomycetes of the genus Case report: A 55-year-old man with a history of autoimmune hepatitis and occupational soil exposure presented with 4-5 week history of progressive cognitive impairment, dysarthria, and right upper extremity weakness. Two months earlier, he had been treated with high-dose corticosteroids and azathioprine and prescribed trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis, which had been interrupted for an estimated 2-4 weeks before presentation during ongoing corticosteroid therapy. Upon admission, laboratory tests demonstrated neutrophil-predominant leukocytosis with lymphopenia, and liver function tests showed substantial improvement compared to his initial presentation of autoimmune hepatitis. Neuroimaging revealed multiple ring-enhancing intracerebral lesions with surrounding vasogenic edema. Stereotactic aspiration of a cerebral abscess and drainage of a concurrent retroperitoneal collection grew Conclusion: Disseminated nocardiosis should be considered for immunosuppressed patients with autoimmune hepatitis presenting with subacute neurological decline and ring-enhancing brain lesions, particularly during outpatient immunosuppression transitions when antimicrobial prophylaxis may be interrupted or incompletely reconciled. The patient demonstrated progressive neurological improvement and radiographic abscess reduction after 3 months of susceptibility-guided combination therapy, reinforcing the importance of early tissue diagnosis and neurosurgical intervention in this population.