Miliary tuberculosis
Encyclopedia
Miliary tuberculosis is a form of tuberculosis
that is characterized by a wide dissemination into the human body and by the tiny size of the lesions (1–5 mm). Its name comes from a distinctive pattern seen on a chest X-ray
of many tiny spots distributed throughout the lung fields with the appearance similar to millet
seeds—thus the term "miliary" tuberculosis. Miliary TB may infect any number of organs, including the lungs, liver, and spleen. It is a complication of 1–3% of all TB cases.
. Miliary tuberculosis can also present with enlarged liver
(40% of cases), enlarged spleen (15%), inflammation of the pancreas
(<5%), and multiple organ dysfunction
with adrenal insufficiency
(adrenal glands do not produce enough steriod hormones to regulate organ function). Stool may also be diarrheal in nature and appearance. The risk factors for contracting miliary tuberculosis are being in direct contact with a person who has it, living in unsanitary conditions, and having an unhealthy diet. People in the U.S. that are at a higher risk for contracting the disease include the homeless and persons living with HIV/AIDS
.
. Tests include chest x-ray
, sputum culture
, bronchoscopy
, TB skin test, open lung biopsy
, head CT
/MRI, blood cultures, fundoscopy, and electrocardiography. A variety of neurological complications have been noted in miliary tuberculosis patients—tuberculous meningitis and cerebral tuberculomas being the most frequent. However, a majority of patients improve following antituberculous treatment.
. The standard treatment recommended by the WHO is with isoniazid
and rifampicin
for six months, as well as ethambutol
and pyrazinamide
for the first two months. If there is evidence of meningitis
, then treatment is extended to twelve months. The U.S. guidelines recommend nine months' treatment. "Common medication side effects a patient may have such as inflammation of the liver if a patient is taking pyrazinamide, rifampin, and isoniazid. A patient may also have drug resistance to medication, relapse, respiratory failure, and Adult Respiratory Distress Syndrome"
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
that is characterized by a wide dissemination into the human body and by the tiny size of the lesions (1–5 mm). Its name comes from a distinctive pattern seen on a chest X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
of many tiny spots distributed throughout the lung fields with the appearance similar to millet
Millet
The millets are a group of small-seeded species of cereal crops or grains, widely grown around the world for food and fodder. They do not form a taxonomic group, but rather a functional or agronomic one. Their essential similarities are that they are small-seeded grasses grown in difficult...
seeds—thus the term "miliary" tuberculosis. Miliary TB may infect any number of organs, including the lungs, liver, and spleen. It is a complication of 1–3% of all TB cases.
Etiology
Miliary tuberculosis is a form of tuberculous infection in the lung that is the result of erosion of the infection into a pulmonary vein. Once the bacteria reach the left side of the heart and enter the systemic circulation, the result may be to seed organs such as the liver and spleen with said infection. Alternatively, the bacteria may enter the lymph node(s), drain into a systemic vein and eventually reach the right side of the heart. From the right side of the heart, the bacteria may seed—or re-seed as the case may be—the lungs, causing the eponymous "miliary" appearance.Signs and Symptoms
A patient with miliary tuberculosis will tend to present with non-specific signs, such as low grade fever, cough, and enlarged lymph nodesLymphadenopathy
Lymphadenopathy is a term meaning "disease of the lymph nodes." It is, however, almost synonymously used with "swollen/enlarged lymph nodes". It could be due to infection, auto-immune disease, or malignancy....
. Miliary tuberculosis can also present with enlarged liver
Hepatomegaly
Hepatomegaly is the condition of having an enlarged liver. It is a nonspecific medical sign having many causes, which can broadly be broken down into infection, direct toxicity, hepatic tumours, or metabolic disorder. Often, hepatomegaly will present as an abdominal mass...
(40% of cases), enlarged spleen (15%), inflammation of the pancreas
Pancreatitis
Pancreatitis is inflammation of the pancreas. It occurs when pancreatic enzymes that digest food are activated in the pancreas instead of the small intestine. It may be acute – beginning suddenly and lasting a few days, or chronic – occurring over many years...
(<5%), and multiple organ dysfunction
Multiple organ dysfunction syndrome
Multiple organ dysfunction syndrome ', previously known as multiple organ failure or multisystem organ failure , is altered organ function in an acutely ill patient requiring medical intervention to achieve homeostasis...
with adrenal insufficiency
Adrenal insufficiency
Adrenal insufficiency is a condition in which the adrenal glands, located above the kidneys, do not produce adequate amounts of steroid hormones , primarily cortisol, but may also include impaired aldosterone production which regulates sodium, potassium and water retention...
(adrenal glands do not produce enough steriod hormones to regulate organ function). Stool may also be diarrheal in nature and appearance. The risk factors for contracting miliary tuberculosis are being in direct contact with a person who has it, living in unsanitary conditions, and having an unhealthy diet. People in the U.S. that are at a higher risk for contracting the disease include the homeless and persons living with HIV/AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
.
Tests
Testing for miliary tuberculosis is conducted in the same manner as for other forms of tuberculosisTuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
. Tests include chest x-ray
Chest X-ray
In medicine, a chest radiograph, commonly called a chest X-ray , is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures...
, sputum culture
Sputum culture
A sputum culture is a test to detect and identify bacteria or fungi that infect the lungs or breathing passages. Sputum is a thick fluid produced in the lungs and in the adjacent airways. A sample of sputum is placed in a sterile container and sent to the laboratory for testing...
, bronchoscopy
Bronchoscopy
Bronchoscopy is a technique of visualizing the inside of the airways for diagnostic and therapeutic purposes. An instrument is inserted into the airways, usually through the nose or mouth, or occasionally through a tracheostomy. This allows the practitioner to examine the patient's airways for...
, TB skin test, open lung biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
, head CT
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
/MRI, blood cultures, fundoscopy, and electrocardiography. A variety of neurological complications have been noted in miliary tuberculosis patients—tuberculous meningitis and cerebral tuberculomas being the most frequent. However, a majority of patients improve following antituberculous treatment.
Treatment
Miliary TB is a serious condition. Cases of miliary TB in patients who remain untreated are nearly 100% fatal. About 25% of patients with miliary TB also have tuberculous meningitisTuberculous meningitis
Tuberculous meningitis is also known as TB meningitis or tubercular meningitis.Tuberculous meningitis is Mycobacterium tuberculosis infection of the meninges—the system of membranes which envelops the central nervous system. It is the most common form of CNS tuberculosis.-Clinical features:Fever...
. The standard treatment recommended by the WHO is with isoniazid
Isoniazid
Isoniazid , also known as isonicotinylhydrazine , is an organic compound that is the first-line antituberculosis medication in prevention and treatment. It was first discovered in 1912, and later in 1951 it was found to be effective against tuberculosis by inhibiting its mycolic acid...
and rifampicin
Rifampicin
Rifampicin or rifampin is a bactericidal antibiotic drug of the rifamycin group. It is a semisynthetic compound derived from Amycolatopsis rifamycinica ...
for six months, as well as ethambutol
Ethambutol
Ethambutol is a bacteriostatic antimycobacterial drug prescribed to treat tuberculosis. It is usually given in combination with other tuberculosis drugs, such as isoniazid, rifampicin and pyrazinamide....
and pyrazinamide
Pyrazinamide
Pyrazinamide is a drug used to treat tuberculosis. The drug is largely bacteriostatic, but can be bacteriocidal on actively replicating tuberculosis bacteria.-Abbreviations:...
for the first two months. If there is evidence of meningitis
Meningitis
Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...
, then treatment is extended to twelve months. The U.S. guidelines recommend nine months' treatment. "Common medication side effects a patient may have such as inflammation of the liver if a patient is taking pyrazinamide, rifampin, and isoniazid. A patient may also have drug resistance to medication, relapse, respiratory failure, and Adult Respiratory Distress Syndrome"
See also
- Lupus vulgarisLupus vulgarisLupus vulgaris are painful cutaneous tuberculosis skin lesions with nodular appearance, most often on the face around nose, eyelids, lips, cheeks and ears. The lesions may ultimately develop into disfiguring skin ulcers if left untreated...
- Metastatic tuberculous abscess or ulceration
- Thomas WolfeThomas WolfeThomas Clayton Wolfe was a major American novelist of the early 20th century.Wolfe wrote four lengthy novels, plus many short stories, dramatic works and novellas. He is known for mixing highly original, poetic, rhapsodic, and impressionistic prose with autobiographical writing...
- Vítězslava KaprálováVítezslava KaprálováVítězslava Kaprálová was a Czech composer and conductor. Among her teachers were some of the best European composers and conductors of the time - Bohuslav Martinů, Václav Talich, and Charles Münch.-Life:She was a daughter of composer Václav Kaprál...
- List of cutaneous conditions