Cunha Burke A, Krakakis James, McDermott Brian P
Infectious Disease Division, Winthrop-University Hospital, Mineola, New York 11501, USA.
Heart Lung. 2009 Jan-Feb;38(1):77-82. doi: 10.1016/j.hrtlng.2008.03.002. Epub 2008 Oct 1.
Miliary or disseminated Mycobacterium tuberculosis continues to be a difficult diagnostic challenge. The clinical signs and symptoms of miliary tuberculosis (TB) depend on the extent and severity of both pulmonary and extrapulmonary organ involvement. When miliary TB presents as a fever of unknown origin (FUO), the diagnosis of miliary TB can be particularly perplexing. Because only 10% to 20% of patients have a history of antecedent TB, the diagnosis of miliary TB often goes unsuspected until suggested by miliary calcifications on the chest x-ray. High-resolution computed tomography of the chest has enhanced the diagnosis of miliary TB. In patients with miliary TB, acid-fast smear positivity for acid-fast bacilli is low in sputum, urine, and cerebrospinal fluid. Traditionally, miliary TB has been diagnosed by demonstrating granulomas in liver or bone marrow specimens. Transbronchial biopsy may be used when liver and bone marrow biopsies are negative. We present a case of FUO due to miliary TB with miliary calcifications on the chest x-ray but with negative liver and bone marrow biopsies. The clinical diagnosis of miliary TB was further enhanced by finding daily morning temperature spikes characteristic of miliary TB. Morning temperature spikes are associated with only 2 other entities, that is, typhoid fever and periarteritis nodosa, which are unlikely to be confused clinically with miliary TB. Although fever curves/patterns are diagnostically unhelpful in many febrile conditions, characteristic fever curves/patterns are most useful in the most diagnostically difficult cases with obceure fevers, particularly FUOs. Clinicians should take care to analyze the fever curves/patterns in such patients, which may provide an important clue to the diagnosis and prompt specific diagnostic testing.
粟粒性或播散性结核分枝杆菌感染仍然是一个难以诊断的挑战。粟粒性肺结核（TB）的临床体征和症状取决于肺内和肺外器官受累的程度和严重程度。当粟粒性肺结核表现为不明原因发热（FUO）时，粟粒性肺结核的诊断可能会特别令人困惑。由于只有10%至20%的患者有既往结核病史，粟粒性肺结核的诊断常常在胸部X线显示粟粒样钙化提示之前未被怀疑。胸部高分辨率计算机断层扫描增强了粟粒性肺结核的诊断。在粟粒性肺结核患者中，痰液、尿液和脑脊液中抗酸杆菌的抗酸涂片阳性率较低。传统上，粟粒性肺结核是通过在肝脏或骨髓标本中发现肉芽肿来诊断的。当肝脏和骨髓活检结果为阴性时，可采用经支气管活检。我们报告一例因粟粒性肺结核导致的不明原因发热病例，胸部X线有粟粒样钙化，但肝脏和骨髓活检结果为阴性。通过发现粟粒性肺结核特有的每日早晨体温峰值，进一步加强了粟粒性肺结核的临床诊断。早晨体温峰值仅与另外两种疾病相关，即伤寒热和结节性多动脉炎，在临床上不太可能与粟粒性肺结核混淆。尽管发热曲线/模式在许多发热性疾病的诊断中并无帮助，但特征性发热曲线/模式在诊断最困难的不明原因发热病例中最为有用，尤其是不明原因发热。临床医生应注意分析此类患者的发热曲线/模式，这可能为诊断提供重要线索并促使进行特定的诊断检测。
