Corticosteroid-induced exacerbation of cryptic miliary tuberculosis to acute respiratory distress syndrome A case report

Rationale: Steroid is known to cause generalized immunosuppression, thereby increasing the risk of new infection or recurrence of tuberculosis. However, corticosteroid as a culprit for exacerbation of miliary tuberculosis-from a cryptic to an overt form-has rarely been described in the literature. Moreover, miliary tuberculosis is hardly diagnosed in a living patient as a primary cause of ARDS even in TB-endemic regions. To the best of our knowledge, this is the first case of a steroid-induced progression of cryptic miliary tuberculosis to ARDS, provided with clear depiction of its radiologic evolution. Patient concerns: A 36-year-old male was treated with corticosteroid under suspicion of adult onset still's disease for six-week history of fever. Within 2 weeks since the initiation of corticosteroid therapy, the patient experienced acute exacerbation of cryptic miliary tuberculosis, which evolved to an overt form, appearing as miliary nodules on both chest radiograph and HRCT. Then, his condition suddenly deteriorated to severe acute respiratory distress syndrome in less than a day. Diagnosis: The final diagnosis was miliary tuberculosis complicated by severe acute respiratory distress syndrome. Interventions: The patient was placed on classic quadruple anti-TB treatment (isoniazide, ethambutol, rifampin, and pyrazinamide). Outcomes: His fever subsided in about 6 weeks and 3 consecutive sputum AFB smears collected on different days were confirmed negative. Diffuse infiltrates on his chest x-ray were completely resolved. Lessons: The case described here draws a clinical and radiological picture of how an occult form of miliary TB evolved to an overt form with use of steroid, and then suddenly progressed to acute respiratory distress syndrome in an immunocompetent young male. This raises awareness on the potential risk of using corticosteroid in patients with cryptic miliary TB. There is formidable challenge in the diagnosis of miliary TB, especially in the early stages. Atypical or even normal outcomes of clinical, microbiochemical, and radiologic evaluation should not be overlooked and dedicated diagnostic work-up should be performed. For equivocal cases, active surveillance with serial radiographs can be helpful.