Lecture topic:
«Focal, disseminated and miliar tuberculosis.
The clinic, diagnostics, differential diagnostics, outcomes.»
Lecturer: Dr Babaeva I.Yu.
SECONDARY, REINFECTIOUS (POST- PRIMARY) TUBERCULOSIS
develops usually in an adult who has previously had a primary infection.
The pathogenesis of secondary tuberculosis is either endogenous under favorable epidemiological conditions or exogenous under epidemic conditions. A combination of exacerbation (endogenous reactivation) of latent foci of superinfections is possible.
FOCAL PULMONARY TUBERCULOSIS–is a clinical form of tuberculosis that unites lesions of different pathogenesis, morphological and clinical and radiological manifestations, in which the diameter of each pathological entity is less than 12 mm, i.e., does not exceed the transverse size of the lobule of the lung.
A distinctive feature of focal pulmonary tuberculosis is considered to be a limited tuberculous lesion, which is localized in individual isolated lung lobules of 1 to 2 segments.
Focal pulmonary tuberculosis is the result of the formation of endogenous, post-primary, or reinfection foci, which can be single or multiple.
CLINIC OF FOCAL TUBERCULOSIS:
1.Low-symptomatic: symptoms of intoxication and respiratory damage are absent in 1/3 of patients. The progression of fresh focal pulmonary tuberculosis is manifested by increased intoxication and the appearance of cough with a small amount of sputum.
2.In exacerbation of chronic focal pulmonary tuberculosis: symptoms of intoxication, cough with sputum, in some cases, small hemoptysis, depression of the supraclavicular space, narrowing of the Krenig fields, shortening of percussion sound, harsh breathing and local dry rales over the affected area.
X-RAY CHARACTERISTICS:
1.A shadow or group of shadows in the lungs up to 1 cm in diameter.
2.The shape of the shadows is irregular or rounded.
3.The intensity of shadows is different.
4.Contours of the shadows are indistinct or clear.
5.Focal shadows are located within 1 or 2 lung segments on one or both sides.
FEATURES OF FOCAL PULMONARY
TUBERCULOSIS IN CHILDREN AND
ADOLESCENTS
1.Secondary forms of tuberculosis in children occur only at high school age, coinciding with puberty (13-14 years old)
2.Adolescents are characterized by secondary forms of primary genesis (against the background of a widespread pulmonary process, there are ITLN affected by tuberculosis).
Differential diagnosis
1.Tuberculosis of the small bronchi (tuberculous endobronchitis).
2.Hypoventilation of part of the lung in tumors of the segmental bronchi.
3.Bronchopneumonia.
4.Disseminated processes in the lungs.
5.Bullous emphysema, abnormal development of the ribs, arteriovenous aneurysm.
VARIANTS OF DISSEMINATED PULMONARY TUBERCULOSIS DEPENDING ON THE EXTENT OF THE LESION:
1.Generalized.
2.With predominant involvement of the lungs.
3.With predominant involvement of other organs.
VARIANTS OF DISSEMINATED PULMONARY TUBERCULOSIS DEPENDING ON THE ROUTE OF MBT SPREAD:
1.Hematogenic.
2.Lymphohematogenic.
3.Lymphogenic.
ACUTE DISSEMINATED PULMONARY TUBERCULOSIS (MILIARY).
It occurs with a significant decrease in TB immunity and massive bacteremia. Hyperergic reaction of pulmonary capillaries to bacterial aggression with significant increase in permeability of their walls creates conditions for MBT penetration into alveolar septa and alveolar walls. In the course of capillaries, multiple single-type prosovoid, yellowish-gray foci appear almost simultaneously, in the form of tubercles 1 - 2 mm in diameter and localized uniformly in both lungs. Edema and cellular infiltration of interalveolar septa significantly reduce elasticity of lung tissue. Exudative or caseous-necrotic reaction is very quickly replaced by productive one, so there is no foci fusion.