Miliary TB: Symptoms, Causes & Treatment

Miliary TB is a severe and widespread form of tuberculosis that creates tiny lesions resembling millet seeds in multiple organs. It can cause symptoms such as fever, generalized weakness, cough, shortness of breath, night sweats, and nausea.

This condition develops when Mycobacterium tuberculosis spreads through the lymphatic system or bloodstream. As a result, it can affect organs such as the intestines, liver, bones, joints, spine, bone marrow, skin, heart, kidneys, and central nervous system.

Treatment for miliary TB is managed by an infectious disease specialist and may include a combination of antibiotics, corticosteroids, hospitalization, or surgery. Early treatment is essential to control the infection and prevent serious complications.

Main symptoms

The main symptoms of miliary TB include:

• Fever that does not improve and chills

• Generalized weakness and excessive fatigue

• Loss of appetite and weight loss

• Dry cough or cough with mucus or blood

• Shortness of breath that worsens over time

• Chest or abdominal pain

• Nausea and vomiting

These symptoms typically appear in the early stages of miliary TB and may also include night sweats, severe anemia, or a skin rash.

Symptoms can vary depending on the affected organ and may include bowel obstruction, fluid buildup in the abdomen (ascites), hypoglycemia, low blood pressure, or darkening of the skin.

Confirming a diagnosis

Miliary TB is diagnosed by an infectious disease specialist or primary care provider based on symptoms, medical history, prior pulmonary tuberculosis, physical examination, and lab tests.

The provider may order tests such as a complete blood count (CBC), liver function tests (LFTs), blood electrolytes, a tuberculin (TB) skin test, and cultures to detect the bacteria in samples of sputum, blood, urine, or cerebrospinal fluid (CSF) obtained through a lumbar puncture (spinal tap).

Additional tests may include a biopsy of affected tissue and imaging studies such as a chest X-ray, ultrasound, CT scan, MRI, or echocardiogram, depending on the symptoms and organs involved.

Possible causes

The main causes of miliary TB include:

• Active pulmonary tuberculosis

• History of pulmonary tuberculosis

• Weakened immune system

• HIV infection

• Diabetes mellitus or malnutrition

• Advanced kidney disease

Other factors that increase the risk include cancer, organ transplantation, and excessive alcohol use, and people with weakened immune systems are at higher risk of developing disseminated forms of tuberculosis according to the World Health Organization (WHO).

Miliary TB is also more common in older adults and children under 4 years of age due to weaker immune defenses.

Types of miliary TB

Miliary TB can be classified into different types depending on the symptoms:

1. Acute classic miliary TB

This type usually affects people under 40 and children. It commonly causes fever later in the day, early morning fever spikes, and night sweats lasting 1 to 2 weeks.

It can affect multiple organs, including the intestines, liver, peritoneum, eyes, bones, spine, bone marrow, skin, heart, kidneys, joints, and central nervous system.

Complications may include adrenal insufficiency, paraplegia, septic arthritis, endocarditis, acute kidney injury, or tuberculous meningitis.

2. Cryptic miliary TB

This form typically affects people over 60 and can be difficult to diagnose. It may present with a negative tuberculin skin test, a normal chest X-ray, and no typical tuberculosis symptoms.

Some people may develop an enlarged liver and spleen, acute respiratory distress syndrome, pneumothorax, endocarditis, or septic shock.

3. Non-reactive disseminated miliary TB

This type occurs when the immune system does not respond effectively to the infection, often due to immune suppression or a high bacterial load.

The bacteria spread widely throughout the body, and typical lesions may be poorly formed or absent due to a limited inflammatory response.

Treatment options

Treatment for miliary TB should always be guided by an infectious disease specialist to eliminate the bacteria and prevent complications.

The main treatment options include a combination of antibiotics such as rifampin, isoniazid, pyrazinamide, and ethambutol, which are recommended as first-line therapy for active tuberculosis disease according to the CDC.

Additional treatments may include:

• Corticosteroids used alongside antibiotics in cases of brain involvement, meningitis, pericardial or pleural effusion, or kidney inflammation

• Nutritional support, especially for people with malnutrition

• Hospitalization to manage complications

• Mechanical ventilation in cases of acute respiratory distress syndrome

• Surgery for complications such as bowel obstruction, perforation, or brain involvement

Treatment varies depending on the organs affected, but antibiotic therapy prescribed by a doctor is essential in all cases.

Is it curable?

Miliary TB can be cured when treatment starts early and follows medical guidance, allowing for full recovery.

However, delays in diagnosis or treatment can lead to serious, life-threatening complications.

Possible complications

Miliary TB may lead to complications such as acute respiratory distress syndrome, pneumothorax, fluid around the heart (pericardial effusion), fluid in the lungs (pleural effusion), myocarditis, or endocarditis.

Other complications include glomerulonephritis, mycotic aneurysm of the aorta, tuberculous meningitis, bone marrow suppression, multiple organ dysfunction syndrome, and disseminated intravascular coagulation (DIC).

Prompt treatment is essential to reduce the risk of complications that can be life-threatening.