Walgrens time table for tb full details for md exam answer 15
Walgren timetable tuberculosis TB natural history MD exam
Wallgren timetable tuberculosis primary TB timeline stages
Wallgren timetable TB detailed timeline erythema nodosum phlyctenular conjunctivitis TB meningitis bones renal MD exam pediatrics
Wallgren timetable TB complete detailed 3 weeks 3 months 6 months 3 years primary infection manifestations exam notes
Wallgren timetable TB complete timeline weeks months years all manifestations
| Event | Details |
|---|---|
| Bacillary implantation in lung | → Ghon focus (subpleural granuloma, lower/mid lobe) |
| Lymphatic spread | → Hilar lymphadenopathy → Ghon complex (focus + node) |
| Clinical features | Usually asymptomatic or mild fever, malaise |
| Tuberculin skin test (TST) | Converts positive at 3–6 weeks post-infection |
| CXR | Subpleural nodule + hilar/mediastinal lymphadenopathy |
Key exam point: TST conversion is the hallmark of this phase. The patient is TST-negative early, then converts.
| Event | Details |
|---|---|
| Hematogenous dissemination | Peak risk of bacteraemic spread |
| Miliary TB | Uniform 1–3 mm random nodules on CXR/HRCT |
| TB Meningitis | Most dangerous; subacute onset 3–6 weeks of symptoms; affects children <4 years primarily |
| Erythema nodosum | Hypersensitivity reaction (immune response to mycobacterial antigen) |
| Phlyctenular conjunctivitis | Hypersensitivity eye manifestation |
| Progressive primary TB | Consolidation with central necrosis |
Key exam point: Miliary TB and TB meningitis occur 2–6 months after primary infection; peak dissemination risk window is 6 weeks–3 months. TB meningitis is the most feared complication in young children.
| Event | Details |
|---|---|
| Progressive primary pulmonary TB | Lobar/segmental consolidation |
| Pleural effusion (primary) | Serous exudative pleural effusion |
| Lymph node compression | Endobronchial disease, collapse-consolidation |
| Superficial lymphadenopathy | Cervical, axillary TB adenitis begins |
Key exam point: Pleural effusion in primary TB = hypersensitivity reaction, usually unilateral.
| Event | Details |
|---|---|
| TB lymphadenitis (adenitis) | Most common form of extrapulmonary TB in children |
| Cervical nodes most common | "Cold abscess" → scrofuloderma if skin involved |
| Mediastinal adenopathy | Can cause obstructive features |
Classic exam statement: TB adenitis classically develops 3–9 months after primary infection.
| Event | Details |
|---|---|
| Abdominal TB | Peritoneal, mesenteric adenitis, ileocaecal |
| Spinal TB (Pott's disease) | Thoracolumbar junction most common |
| Early skeletal TB | Especially dactylitis (Spina ventosa) in children |
| Event | Details |
|---|---|
| Bones and joints TB | Several years (5–7 years) after primary infection |
| Pott's spine | Thoracolumbar junction; vertebral collapse, gibbus deformity |
| Hip, knee involvement | Weight-bearing joints |
| Dactylitis | Short tubular bones of hands/feet in children |
Key exam point: Skeletal TB = several years after primary infection.
| Event | Details |
|---|---|
| Renal TB | >10 years after primary infection; "sterile pyuria" |
| Genital TB | Female > Male; commonest cause of infertility in endemic areas |
| Clinical clue | Pyuria with sterile urine culture = suspect renal TB |
Key exam point: Renal and genital TB may take over a decade to manifest.
| Event | Details |
|---|---|
| Reactivation of dormant foci | Reactivation TB (secondary/post-primary) |
| Cavitary pulmonary TB | Apical/upper lobe predominance; high bacillary burden |
| Target group | Immunosuppression, malnutrition, steroid use, HIV |
| CXR | Thick-walled cavities, tree-in-bud pattern, fibrosis |
| Time After Primary Infection | Event/Complication |
|---|---|
| 0–6 weeks | Ghon focus, Ghon complex; TST converts |
| 6 weeks – 3 months | PEAK DISSEMINATION → Miliary TB, TB Meningitis, Erythema nodosum, Phlyctenular conjunctivitis |
| 3–6 months | Progressive primary pneumonia, Pleural effusion |
| 3–9 months | TB Adenitis (cervical lymphadenopathy) |
| 6 months – 2 years | Abdominal TB, early Pott's spine |
| Several years (5–7 yr) | Bones & Joints TB (Pott's spine, hip, dactylitis) |
| >10 years | Renal TB, Genital TB |
| >2 years | Reactivation/Post-primary TB (cavitary) |