2. PRIMARY PULMONARY TB Clinical Features: (in children) No symptoms or signs and passes unnoticed in the majority of cases  characterized by 1ry lesion with affection of draining lymph nodes (primary complex) which may occur in: The lungs with enlargement of the mediastinal LNs The tonsils with enlargement of the cervical LNs Intestine with enlargement of the mesenteric LNs

3. Febrile illness (mild and lasts for 7 -14 ds) but other systemic features of TB infection may accompany it. It may be accompanied by erythema nodosum (bluish-red, raised, tender cutaneous lesions on shins and thighs associated with polyarthlagia) which can also occur in other diseases. Progressive course occasionally occurs  dry pleurisy or pleural effusion, lobar or segmental collapse, acute military TB, TB meningitis & post- primary pulmonary TB.

5. Differential Diagnosis: Other causes of febrile illnesses such as influenza, acute bronchitis, pneumonia and infectious mononucleosis. Other causes of hilar lymph node enlargement such as sarcoidis and reticulosis.

6. Complications: Collapse and consolidation (epituberculosis). Bronchiectasis. Obstructive emphysema. Broncholith: calcification in a lymph node that may be extruded into a bronchus.

7. Diagnosis: X-ray chest usually shows: - Unilateral enlargement of hilar LNs - The primary intrapulmonary lesion if it is large enough. - Complications as pleural effusion, collapse and acute pneumonic tuberculosis may be superimposed.

8. Tuberculin test: (Mantoux technique) - Material: a purified protein derivative (PPD) tuberculin - Route: injected intradermally - Site: in the flexor aspect of the forearm. - Result: positive if a raised area of inflammatory edema (not less than 5 mm in diameter) with surrounding erythema occurs within 2-3 days. - Dose: 2 tuberculin units and if there is no reaction it should be repeated with 5 units.

9. - Reaction: It is a delayed type hypersensitivity reaction that detects previous or present exposure to tubercle bacilli. - Benefit: examination of the family contacts of cases of TB & indicates which of the contacts should be vaccinated with BCG. - False negative test is present in severe miliary TB, tuberculous meningitis, within 8 weeks from onset of infection, sarcoidosis and lymphoma and in immunosuppressed patients.

10. Bacteriological examination: Tubercle bacilli can sometimes be identified by direct examination or by culture of fasting gastric juice or of secretions from the larynx. The isolation of tubercle bacilli is an absolute proof of the diagnosis of tuberculosis. Serological tests & examination of clinical specimens by PCR may be helpful.

11. MILIARY TUBERCULOSIS Clinical Features: (more in children, young adults & immunosuppressed pts) It may start suddenly or may be preceded by a few weeks of vague ill health. There is high fever, loss of weight, progressive anemia, cough and dyspnea. There may be no signs other than scattered fine crepitations all over the chest.

12. The liver is often enlarged, the spleen is palpable and tender and choroidal tubercles may be visible in the fundus. Leucocytosis is usually absent and the sedimentation rate is high. If chemotherapy is not given, the patient’s condition deteriorates rapidly and death occurs from exhaustion or tuberculous meningitis. The cryptic form occurs in old age with general malaise, loss of weight and anemia. Respiratory symptoms are rare and miliary shadows & choroidal tubercles are absent.

13. Differential Diagnosis: Acute miliary TB must be distinguished from other causes of pyrexia without obvious localizing symptoms or signs such as enteric fever, infective endocarditis, staphylococcal septicemia, subphrenic abscess, acute pulmonary tuberculosis and reticulosis. Complications: Adult respiratory distress syndrome. Immune complex nephritis.

14. Diagnosis: Symptoms of fever, progressive clinical deterioration, persistent pyrexia and splenomegaly  early suspicion Chest x-ray shows miliary shadows symmetrically distributed over both lungs Fundus examination may reveal choroidal tubercles. Tuberculin test is usually positive but a negative test does not exclude the disease (tuberculin sensitivity may depressed due to severe illness).

16. Direct examination by Ziehl-Neelsen stain and culture of sputum, urine or bone marrow may reveal tubercle bacilli. Examination of sputum or bone marrow by polymerase chain reaction (PCR) may detect tubercle bacilli and also serological studies may detect antibodies against mycobacterial antigens in blood.