What does a positive tuberculin test mean? Primary tuberculosis complex

The focus of tuberculous inflammation in the lungs, which appears after infection, is called the primary affect. The process affects the lymphatic vessels that go to the root of the lungs, and the lymph nodes are also affected. The primary focus of inflammation, together with lymphangitis and lymphadenitis, is called the primary tuberculosis complex. In the current understanding of the mechanism of development of primary forms of tuberculosis, bronchoadenitis is primary or can develop along with changes in lung tissue. How does the primary tuberculosis complex manifest itself? What does a positive tuberculin test indicate?

Clinical manifestation of primary tuberculosis complex

The symptoms of the primary tuberculosis complex are varied. In addition to changes in the lung tissue, hepatolienal syndrome and paraspecific reactions in the form of erythema nodosum or phlyctenular conjunctivitis may develop. The primary complex is most often observed in childhood and in most cases begins acutely. Body temperature rises to 38-39⁰C, symptoms of tuberculosis intoxication appear.

The fever lasts for 2-3 weeks, and then it is replaced by subfebrile condition. Recently, the primary tuberculosis complex begins gradually and indistinctly. This is due to the widespread use of intradermal vaccination and chemoprophylaxis. Sputum production and cough are minor. Often children do not cough, but swallow phlegm.

Objective signs of primary tuberculosis complex

On percussion over the affected area of ​​the lung, dullness is noted, hard or weakened breathing is auscultated, dry or wet wheezing.  Mycobacterium tuberculosis is often found when examining sputum or washings from the bronchi. In blood tests, leukocytosis is noted within 10-12x10⁹ in 1 l with a neutrophilic shift to the left and an increase in ESR of approximately 30-50 mm/hour.

Radiologically, a shadow is detected in the lung, in the early stages of the development of the process or during the reverse development, a bipolar lesion may be detected. At the beginning of the disease, against the background of darkening, a vascular pattern of the lungs is visible, which may disappear if the process progresses.

X-ray stages of development of the primary tuberculosis complex:

• First stage – the focus is surrounded by a zone of perifocal inflammation, characterized by the presence of a homogeneous shadow, it is difficult to distinguish it from nonspecific pneumonia.
• Second stage – partial resorption of the infiltrate, bipolarity of the lesion is noted.
• Third stage – hearth inlay and compaction.
• Fourth stage - calcification in the lungs and lymphatic vessels of the mediastinum.

Variants of the course of the primary tuberculosis complex

Signs of the primary tuberculosis complex are not always recognized in the initial period of development, since the process can be hidden under the guise of influenza, pneumonia and dyspepsia. Allocate complicated and uncomplicated course of the process. With an uncomplicated primary tuberculosis complex, the healing process proceeds by resorption of the focus or replacement of granulation tissue with fibrous tissue.

In an unfavorable course, foci of lymphohematogenous seeding appear  against the background of a perifocal reaction, pleurisy develops. Foci in the lungs are found only after resorption of the exudate. Foci of lymphohematogenous seeding are more often localized in the area of ​​the apex of the lung. After compaction and calcification, such lesions are called Simon's lesions. The primary affect can turn into caseous pneumonia, disintegrate, resulting in the formation of multiple cavities in the lungs, that is, early primary cavities.

What is the outcome of a primary tuberculosis complex?

In addition to specific complications after a primary tuberculous complex, bronchiectasis and atelectasis may form, for the elimination of which surgery is indicated.

The consequences of the primary tuberculosis complex depend on the state of the body, the timeliness of diagnosis and treatment. More often the primary complex has a benign course. The process ends abortively, there is a stable clinical recovery with the development of relative immunity. At the same time, the person retains a positive tuberculin reaction. Biological recovery is also possible, as evidenced by the complete disappearance of foci and a negative tuberculin reaction. The most unfavorable outcome of the primary tuberculosis complex in early childhood.

Date  and conditions for the treatment of primary tuberculosis complex

Treatment is carried out with the help of anti-tuberculosis and restorative drugs for 6 months in a hospital or sanatorium, as well as for 2-4 months on an outpatient basis. Thanks to the implementation of specific treatment, the percentage of cure of patients with primary tuberculosis complex has significantly increased, there are almost no lethal cases. In cases where there are fibrous-cavernous changes in the lungs or large caseous foci (caseoma), lung resection and lobectomy are indicated.

Thus, when detecting a positive tuberculin test, it is important to remember that this may be the result of an abortive course and clinical recovery after a primary tuberculosis complex.