Tuberculosis Study Guide - M.M. Savula 2002

Secondary forms of pulmonary tuberculosis
Focal pulmonary tuberculosis

Secondary forms of tuberculosis develop in long-term infected individuals due to the reactivation of old residual lesions formed during the primary infection with Mycobacterium tuberculosis, or As a result of a new, repeated infection.

Focal Pulmonary Tuberculosis is a limited, "minor" form of pulmonary tuberculosis characterized by tuberculous foci up to 1 cm in size, located in one or both Lungs, generally occupying no more than 1–2 segments.

Pathogenesis. Focal forms include both recently developed, fresh (soft-focal) lesions and older ones with elements of scar tissue but showing signs of active disease (fibro-focal). Such fibro-focal changes may result from incomplete resolution of soft-focal tuberculosis or Other forms of tuberculosis, such as infiltrative.

Clinical Features and Diagnosis. Since the affected area in this form of tuberculosis is small, the disease is often asymptomatic or oligosymptomatic, and patients rarely seek medical attention. Therefore, screening fluorography is of great importance for its detection. Sometimes patients complain of general weakness, sweating, a mild cough, occasionally producing a small amount of sputum, and note an intermittent low-grade fever, which is often not subjectively felt.

There are usually no abnormalities in the Percussion sound in focal tuberculosis; breathing is vesicular, occasionally harsh over the apex of the lung or below the clavicle. Very rarely (with the progression and breakdown of foci), fine moist crackles may be heard over a limited area of the lungs after coughing.

Peripheral Blood counts are unchanged, or there may be a slight increase in the ESR. Mycobacteria are rarely found in the sputum. The Mantoux test is positive.

The primary diagnostic method is X-ray imaging. In the apices of the lungs or below the clavicle, a few focal opacities (up to 1 cm in size) of varying intensity with more or less distinct margins are detected (Fig. 5).

Focal tuberculosis responds well to Treatment, although complete resolution of the foci rarely occurs; they scar over and sometimes partially calcify.

When fluorography reveals foci with elements of scarring, it is not always easy to determine whether the process is fully healed. In such individuals, a TB specialist determines The activity of the tuberculous process. Clinical symptoms, radiological signs, blood tests, and tuberculin tests (subcutaneous Koch's test) are taken into account; sputum or bronchial washings are repeatedly examined for MTB, and in unclear cases, trial treatment with anti-tuberculosis drugs is prescribed. If the activity of the tuberculous foci is confirmed, the patient continues treatment; if it is ruled out, treatment is discontinued, and the patient is advised to undergo a fluorographic examination once a year.