19. Focal and infiltrative – pneumonic tuberculosis

Focal pulmonary tuberculosis

What is it?

• It is the small form of tuberculosis
• Characterized by the presence of a few foci, predominantly of productive nature

Etiology

• The most often source of focal pulmonary tuberculosis is the residual foci (foci seeding), which one were derivated during a primary tuberculous infection

Pathogenesis

• Most often focal tuberculosis arises as a consequence of reactivation of residual changes of tuberculous infection in the person
• Reactivation of the initial tuberculous infection results in symptoms and spread of mycobacteria

Forms

• Soft focal- this form shows symptoms
• Fibrosis focal

Symptoms

• Only some patients have subfebrile condition for a long time
• Vegetovascular dystonia
• Sweating
• Tachycardia
• Decrease of work ability, fatigue is subjectively marked
• Cough without sputum

Diagnosis

• Blood tests- appear relatively normal
• Microscopic sputum examination
• Broncho-alevolar lavage
• X-ray- in the lung apical segments there are polymorphic focal shadows

Infiltrative pulmonary tuberculosis

What is it?

• This is a secondary form of tuberculosis
• Characterized by formation in the lung focus with more than 1см in diameter
• The infiltrates may appear in the intact lung but more often they arise on a background of the aged foci

Etiology

• May be as a result of the progress of the new foci of TB
• Its formation is also possible as a result of lymphogenic spreading of mycobacteria from the caseous lymphatic nodes of the mediastinum.

Pathogenesis

• The tuberculous infiltration is a tuberculous focus with a perifocal inflammation. The focus has specific structure, perifocal inflammation is serous
• There is the exudate in alveoli, sometimes with a lot of alveolar macrophages, sometimes with an impurity of leucocytes, lymphocytes and fibrin
• Infiltrative tuberculosis is characterized by formation of disintegration
• The bacteria infect and multiply within the lung tissue, leading to inflammation, tissue damage, and the formation of granulomas.

Symptoms

• Persistent cough
• Chest pain
• Shortness of breath
• Fatigue
• Weight loss
• Night sweats
• Fever

Physical exam

Palpation

• Painfullness is marked on palpation of thoracic and dorsal muscles

Percussion

• Dullness of sound in the lung parenchyme

Auscultation

• If there is cavern then fine and coarse bubbling rales are often heard

Diagnosis

• X-ray- infiltrate is determined as a diffusal with indistinct shadow of small intensity
• The round infiltrates are shadows with clear contours
• Nodules and cavitation may be observed
• Sputum testing
• TST
• Blood testing