Reactivation tuberculosis is usually seen at –
Correct Answer: Apical and posterior segments of upper lobes
Description: Ans is 'a' i.e., Apical and posterior segments of upper lobes Postprimary (adult-type) disease/Reactivation (Secondary) tuberculosis* Also referred to as reactivation or secondary TB, postprimary TB is probably most accurately termed adult-type TB, since it may result from endogenous reactivation of distant latent infection or recent infection (primary infection or reinfection).* It is usually localized to the apical and posterior segments of the upper lobes, where the substantially higher mean oxygen tension (compared with that in the lower zones) favors mycobacterial growth.* The extent of lung parenchymal involvement varies greatly, from small infiltrates to extensive cavitary disease. With cavity formation, liquefied necrotic contents are ultimately discharged into the airways and may undergo bronchogenic spread, resulting in satellite lesions within the lungs that may in turn undergo.* Massive involvement of pulmonary segments or lobes, with coalescence of lesions, produces caseating pneumonia.* While up to one-third of untreated patients reportedly succumb to severe pulmonary TB within a few months after onset (the classic "galloping consumption" of the past), others may undergo a process of spontaneous remission or proceed along a chronic, progressively debilitating course ("consumption" or phthisis).* Early in the course of disease, symptoms and signs are often nonspecific and insidious, consisting mainly of diurnal fever and night sweats due to defervescence, weight loss, anorexia, general malaise, and weakness. However, in up to 90% of cases, cough eventually develops--often initially nonproductive and limited to the morning and subsequently accompanied by the production of purulent sputum, sometimes with blood streaking.* Hemoptysis develops in 20-30% of cases, and massive hemoptysis may ensue as a consequence of the erosion of a blood vessel in the wall of a cavity.* Hemoptysis, however, may also result from rupture of a dilated vessel in a cavity (Rasmussen's aneurysm) or from aspergilloma formation in an old cavity.* The most common hematologic findings are mild anemia, leukocytosis, and thrombocytosis with a slightly elevated erythrocyte sedimentation rate and/or C-reactive protein level.
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