Miliary Tuberculosis: A Comprehensive Review of Epidemiology, Clinical Manifestations, Diagnosis, Treatment, and Complications

Abstract

Abstract Miliary tuberculosis (TB) represents a potentially fatal form of disseminated TB resulting from the lymphohematogenous dissemination of Mycobacterium tuberculosis. Although accounting for approximately 1–2% of all TB cases in immunocompetent adults, its mortality rate exceeds 30%. This review screened peer-reviewed, original research studies via four databases (PubMed, EMBASE, MEDLINE, and CENTRAL) to synthesize up-to-date evidence. Key risk factors include human immunodeficiency virus (HIV) co-infection, anti-tumor necrosis factor-α (TNF-α) agents and chronic malnutrition. The clinical presentation of miliary TB is notoriously nonspecific, with fever, night sweats, weight loss, and constitutional symptoms predominating. Over 60% of patients have extrapulmonary complications, with central nervous system (CNS) involvement in 10–30%, abdominal involvement in 15–30%, and skeletal involvement in up to 17%. Laboratory abnormalities are common, including elevated erythrocyte sedimentation rate (ESR), anemia, lymphopenia, and nearly universal C-reactive protein (CRP) elevation. Diagnoses remain difficult due to paucibacillary lesions; novel molecular assays and a validated CNS prediction scoring system greatly improve diagnostic efficiency, while multiple microbiological and invasive tissue sampling modalities are briefly summarized for comprehensive clinical reference. Standard 6-month isoniazid, rifampicin, pyrazinamide ethambutol and isoniazid, rifampicin (HRZE-HR) regimens apply to isolated pulmonary miliary TB, whereas 9–12-month extended therapy plus adjunctive dexamethasone is required for CNS complications. Drug resistant cases demand 18–24-month individualized regimens with high blood-brain barrier penetration. Severe complications including tuberculous meningitis and high mortality acute respiratory distress syndrome (ARDS) are fully discussed, and TNF-α antagonists act as salvage therapy for steroid-refractory tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS). Bacillus Calmette–Guérin (BCG) vaccination provides substantial protection against miliary TB in children, with efficacy of approximately 77% and favorable cost-effectiveness. Existing reviews lack integrated post-pandemic epidemiological data, cutting-edge molecular diagnostics and modern extrapulmonary treatment algorithms; this paper fills such gaps to offer balanced clinical guidance for frontline clinicians.