Physiopathology of Extrapulmonary Tuberculosis: A Literature Review

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Introduction: Extrapulmonary tuberculosis (EPTB) is an infection by mycobacteria in any part of the body other than the lungs. There is information on tuberculosis infection from more than 3,000 years ago, and despite the knowledge that there is about the disease, nowadays, it is estimated that a quarter of the world population is infected and 15% of the cases are extrapulmonary.

Aims: This literature review aims to present the physiopathology of the most common EPTB, update and summarize the current diagnostic and therapeutic advances for the EPTB reviewed, as well as describe the physiopathological implications of coinfection with human immunodeficiency virus (HIV).

Methods: A literature review was performed for which PubMed, Cochrane Library, and Google Scholar databases were consulted using the following keywords: Tuberculosis, Epidemiology, Physiopathology, Diagnosis, and Therapy. Only articles published from 2016 to 2022, evaluated with a score ≥ 10 based on the Scale for the Assessment of Narrative Review Articles (SANRA) score were included, obtaining a total of 38 bibliographic sources.

Discussion: Depending on the system or organ affected, it is how the physiopathological process is carried through as well as how the clinical features manifest and the diagnostic approach is made. The diagnostic and therapeutic strategies of each type of EPTB have been widely studied; however, although technological innovation has contributed to the development of new diagnostic techniques, the treatment of almost all EPTB has remained the same over time, which consists of the same 6-month regimen of therapy as in pulmonary tuberculosis. Furthermore, tuberculosis treatment has been severely affected by rifampicin resistance and concomitant HIV infection.

Conclusion: The physiopathology of the different EPTBs is well described; nevertheless, a better understanding of how the disease spreads and develops will allow us to create new diagnostic resources and improve therapeutic targets for this disease, which still has a substantial presence worldwide.