Cryptic Tuberculosis – At A Glance

Cryptic tuberculosis an atypical clinical presentation of tuberculosis

Miliary tuberculosis is said to be overt, if the typical miliary infiltrate is seen on the chest x-ray.

But in case of cyptic tuberculosis, typical clinical features and radiological findings are absent.

So this can be accounted as one of the medial dilemmas as it is difficult to be diagnosed.
Cryptic TB

  1. Age over 60 yrs, usually females are more affeced
  2. Intermittent low-grade pyrexia of unknown origin (Rarely occurs)
  3. Unexplained weight loss
  4. General debility
  5. Hepatosplenomegaly in 25–50%
  6. Normal chest X-ray
  7. Blood dyscrasias; leukaemoid reaction, pancytopenia, hypoalbuminaemia
  8. Negative tuberculin skin test / QuantiFERON-TB gold
  9. Negative smear for AFB in up to 50% cases
  10. Confirmation by biopsy with granulomas and/or acid-fast bacilli in liver or bone marrow
  11. Meningitis may occur in the terminal stage

Association with other diseases like – HIV infection, chronic renal disease, diabetes,
immunosuppression, endocrine disorder, malignancy, blood dyscrasias may alter the typical
presentation and atypical presentations often delay or even can lead to missed diagnosis of cryptic

Extent of the disease (Extrapulmonary locations) can be assessed USG, CT scan and MRI
Nowadays, PET CT scans are the tool of evaluation of suspected cryptic TB cases
As this is a diagnostic challenge, patients remained diagnosed till autopsy, but with the advancement of new imaging techniques, now we have the ability to diagnose the disease when the patient is alive.

Confirmation of diagnosis depends upon the histopathological evidence of biopsy specimen and
isolation of the organism in sputum, body fluids (pleural, pericardial, ascitic fluid)

It is wise to implement a therapeutic trial with anti-tubercular drugs, even when the diagnosis is uncertain as delay in treatment is an independent factor for mortality 

Treatment of cryptic TB is done as the same as category 1 of TB which is recommended by WHO
which is…..

  • Intensive phase of 2 months with isoniazide, rifampicine, pyrazinamide, ethambutol
  • Continuation phase of 4 months with isoniazide, rifampicine

Optimal – Daily and daily
Alternatives – Daily and 3 times/week OR 3 times/week and 3 times/week

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