Miliary tuberculosis

Miliary tuberculosis
Classification and external resources
Miliary tuberculosis is characterized by a chronic, contagious bacterial infection caused by Mycobacterium tuberculosis that has spread to other organs of the body by the blood or lymph system.
ICD-10	A19
ICD-9	018
eMedicine	med/1476
MeSH	D014391

Miliary tuberculosis (also known as "disseminated tuberculosis",^[1] "tuberculosis cutis acuta generalisata",^[1] and "Tuberculosis cutis disseminata"^[1]) 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.^[2]

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.^[3] 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.^[3] 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 nodes. 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).^[2] 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.^[4]

Tests

Testing for miliary tuberculosis is conducted in the same manner as for other forms of tuberculosis. Tests include chest x-ray, sputum culture, bronchoscopy, TB skin test, open lung biopsy, head CT/MRI, blood cultures, fundoscopy, and electrocardiography.^[4] 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

Main article: Tuberculosis 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 meningitis. 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.^[5] "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"^[4]

See also

• Lupus vulgaris
• Metastatic tuberculous abscess or ulceration
• Thomas Wolfe
• Vítězslava Kaprálová
• List of cutaneous conditions

References

1. ^ ^{a b c} Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. pp. Chapter 74. ISBN 1-4160-2999-0. 
2. ^ ^{a b} Lessnau, Klaus-Dieter, "Miliary Tuberculosis", http://www.emedicine.com/med/topic1476.htm, October 3, 2006.
3. ^ ^{a b} Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; & Mitchell, Richard N. (2007). Robbins Basic Pathology (8th ed.). Saunders Elsevier. pp. 516-522 ISBN 978-1-4160-2973-1
4. ^ ^{a b c} Dugdale, David, "Disseminated Tuberculosis" http://www.nlm.nih.gov/medlineplus/ency/article/000624htm, December 3, 2008.
5. ^ www.cdc.gov/mmwr/preview/mmwrhtml/rr5211a1.htm

Books and other articles for further reading

• Reichman, Lee B., M.D., M.P.H. & Tanne, Janice H. (2002). "Timebomb: The Global Epidemic of Multi-Drug-Resistant Tuberculosis. Mcgraw-Hill. ISBN 0-07-135924-9

• "The Treatment of Tuberculosis" Albino, Juan & Reichman, Lee. "Respiration" (Respiration 1998;65:237-255)[1]]]

• "How to Combat Tuberculosis in the Year 2000?" Rieder, Hans (Respiration 1998;65:423-431)[2]