Tuberculosis, miliary

Tuberculosis, miliary

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 radiograph 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. Miliary tuberculosis is present in about 2% of all reported cases of tuberculosis and accounts for up to 20% of all extra-pulmonary tuberculosis cases.

Cause of Miliary Tuberculosis 

Miliary tuberculosis is a potentially life-threatening type of tuberculosis that occurs when a large number of the bacteria travel through the bloodstream and spread throughout the body. is a contagious infection caused by the airborne bacteria Mycobacterium tuberculosis.

Symptoms

The symptoms of miliary TB are very general. They can include:

• a fever that goes on for several weeks and may be worse in the evening
• chills
• dry cough that may occasionally be bloody
• fatigue
• weakness
• shortness of breath that increases with time
• poor appetite
• weight loss
• night sweats
• just not feeling well in general

If other organs besides your lungs are infected, these organs may stop working properly. This can cause other symptoms, such as low levels of red blood cells if your bone marrow is affected or a characteristic rash if your skin is involved.

Diagnosis

• Examination and culture of a sample from the infected area
• When available, nucleic acid amplification tests
• Tuberculin skin test or blood tests to detect tuberculosis
• A chest x-ray

Diagnosis of miliary tuberculosis is similar to the diagnosis of pulmonary tuberculosis. Samples of infected fluids may be examined under a microscope and/or sent to a laboratory to be grown (cultured) and tested. Samples may be:

• Blood
• Cerebrospinal fluid, obtained by spinal tap (lumbar puncture)
• Urine
• Fluid from the space between the two layers of the membrane that surrounds the lungs (pleura)
• Fluid from the space between the two layers of the membrane that surrounds the heart (pericardium)
• Joint fluid
• Bone marrow

Mycobacterium tuberculosis can sometimes be identified by doing nucleic acid amplification tests (NAATs) on certain types of samples. 

Note 1: Confirm the recurrence of active infection by culture, histopathology, or other diagnostic laboratory testing.

Note 2: Rate under the appropriate body system any residual disability of infection which includes, but is not limited to, skin conditions and conditions of the respiratory, central nervous, musculoskeletal, ocular, gastrointestinal, and genitourinary systems and those residuals listed in §4.88c.