Extrapulmonary tuberculosis is

tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in ...

(TB) within a location in the body other than the

lungs The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of th ...

. It accounts for an increasing fraction of active cases, from 20 to 40% according to published reports, and causes other kinds of TB. These are collectively denoted as "extrapulmonary tuberculosis". Extrapulmonary TB occurs more commonly in

immunosuppressed Immunosuppression is a reduction of the activation or efficacy of the immune system. Some portions of the immune system itself have immunosuppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse reacti ...

persons and young children. In those with HIV, this occurs in more than 50% of cases. Notable extrapulmonary infection sites include the

pleura The pulmonary pleurae (''sing.'' pleura) are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls. The inner pleura, called the visceral pleura, covers the surface of each lung and dips bet ...

(in tuberculous pleurisy), the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...

(in tuberculous

meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or ...

), the

lymphatic system The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphatic or lymphoid o ...

(in scrofula of the neck), the

genitourinary system The genitourinary system, or urogenital system, are the organs of the reproductive system and the urinary system. These are grouped together because of their proximity to each other, their common embryological origin and the use of common pathwa ...

(in

urogenital tuberculosis Urogenital tuberculosis is a form of tuberculosis that affects the urogenital system. Symptoms *Persistent cystitis, unresponsive to antibiotics. *Urinary frequency *Dysuria *Loin discomfort *Malaise and general symptoms of tuberculosis *Ulcer Ho ...

), and the bones and joints (in

Pott disease Pott disease is tuberculosis of the spine, usually due to haematogenous spread from other sites, often the lungs. The lower thoracic and upper lumbar vertebrae areas of the spine are most often affected. It causes a kind of tuberculous arthriti ...

of the spine), among others. Infection of the

lymph nodes A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that includ ...

, known as tubercular lymphadenitis, is the most common extrapulmonary form of tuberculosis. An ulcer originating from nearby infected lymph nodes may occur and is painless. It typically enlarges slowly and has an appearance of "wash leather". Mycobacterial Infection, Duodenum (4401445363)

Mycobacterial Infection, Duodenum (4401445363)

When it spreads to the bones, it is known as skeletal tuberculosis, a form of

osteomyelitis Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the ...

. Tuberculosis has been present in humans since

ancient times Ancient history is a time period from the beginning of writing and recorded human history to as far as late antiquity. The span of recorded history is roughly 5,000 years, beginning with the Sumerian cuneiform script. Ancient history cov ...

. Central nervous system infections include tuberculous meningitis, intracranial tuberculomas, and spinal tuberculous arachnoiditis.

Gastrointestinal

Abdominal infections include gastrointestinal tuberculosis (which is important to distinguish from

Crohn's disease Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, abdominal distension ...

, since

immunosuppressive therapy Immunosuppression is a reduction of the activation or efficacy of the immune system. Some portions of the immune system itself have immunosuppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse react ...

used for the latter can lead to dissemination), tuberculous peritonitis, and genitourinary tuberculosis. A potentially more serious, widespread form of TB is called "disseminated tuberculosis", also known as

miliary tuberculosis To disseminate (from lat. ''disseminare'' "scattering seeds"), in the field of communication, is to broadcast a message to the public without direct feedback from the audience. Meaning Dissemination takes on the theory of the traditional vie ...

. Miliary TB currently makes up about 10% of extrapulmonary cases.

Pleural effusion

This condition is one of the common forms of extrapulmonary tuberculosis. It occurs during acute phase of the disease, with fever, cough, and pain while breathing (pleurisy). Pleural fluid usually contains mostly lymphocytes and the ''Mycobacterium'' bacteria. Gold standard of diagnosis is the detection of ''Mycobacterium'' in pleural fluid. Other diagnostic test includes the detection of

adenosine deaminase Adenosine deaminase (also known as adenosine aminohydrolase, or ADA) is an enzyme () involved in purine metabolism. It is needed for the breakdown of adenosine from food and for the turnover of nucleic acids in tissues. Its primary function ...

(above 40 U/L) and

interferon gamma Interferon gamma (IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. Wheelock ...

in pleural fluid.

References

{{Tuberculosis Tuberculosis