Peritoneal Tuberculosis

Peritoneal tuberculosis represents 4-10% of all extrapulmonary TB cases in children and remains a significant diagnostic challenge due to its nonspecific presentation.

Epidemiological Features:

• Age distribution: More common in older children
• Gender: Slight female predominance
• Geographic distribution: Higher in TB-endemic regions
• Association with HIV: 17-30% cases

Risk Factors:

• Primary:
  • Contact with TB patients
  • HIV infection
  • Malnutrition
  • Immunosuppression
• Secondary:
  • Diabetes mellitus
  • Cirrhosis
  • Continuous ambulatory peritoneal dialysis
  • Recent abdominal surgery

Pathophysiology

Routes of Infection:

• Hematogenous spread:
  • From primary pulmonary focus
  • Via mesenteric lymphatics
• Direct spread:
  • From infected intestines
  • From fallopian tubes
  • From mesenteric lymph nodes

Pathological Types:

• Wet/Ascitic type (90%):
  • Abundant ascites
  • Multiple small tubercles
  • Inflammatory exudates
• Dry/Plastic type (10%):
  • Thick adhesions
  • Omental thickening
  • Fibrous bands
• Fibrotic/Fixed type:
  • Omental masses
  • Loculated ascites
  • Extensive adhesions

Immunological Response:

• Cell-mediated immunity
• Granuloma formation
• Cytokine release
• Inflammatory cascade

Clinical Features

Symptoms:

• Constitutional symptoms:
  • Fever (80-95%)
  • Weight loss (90%)
  • Night sweats
  • Anorexia
  • Fatigue
• Abdominal symptoms:
  • Abdominal distension (90%)
  • Abdominal pain (80%)
  • Vomiting
  • Altered bowel habits

Physical Findings:

• General examination:
  • Cachexia
  • Pallor
  • Lymphadenopathy
• Abdominal examination:
  • Ascites
  • Abdominal tenderness
  • Doughy abdomen
  • Mass/lump (omental)
  • Hepatosplenomegaly

Diagnosis

Laboratory Studies:

• Blood tests:
  • Complete blood count
  • ESR and CRP
  • Liver function tests
  • Serum albumin
  • HIV testing
• Ascitic fluid analysis:
  • Protein >3 g/dL
  • SAAG <1.1 g/dL
  • Lymphocytic predominance
  • High ADA levels (>33 U/L)
  • Low glucose

Imaging Studies:

• Ultrasound findings:
  • Ascites with septations
  • Omental thickening
  • Lymphadenopathy
  • Peritoneal nodules
• CT findings:
  • Smooth peritoneal thickening
  • Omental caking
  • Mesenteric thickening
  • Loculated ascites
• MRI findings:
  • Enhanced delineation
  • Better soft tissue contrast
  • Evaluation of complications

Confirmatory Tests:

• Microbiological:
  • AFB smear
  • TB culture
  • Gene Xpert MTB/RIF
• Histopathological:
  • Peritoneal biopsy
  • Laparoscopy
  • Mini-laparotomy

Treatment

Anti-tubercular Therapy:

• Intensive phase (2 months):
  • Isoniazid (10 mg/kg)
  • Rifampicin (15 mg/kg)
  • Pyrazinamide (35 mg/kg)
  • Ethambutol (20 mg/kg)
• Continuation phase (4-7 months):
  • Isoniazid
  • Rifampicin

Adjunctive Therapy:

• Corticosteroids:
  • Prednisolone 1 mg/kg/day
  • Duration: 4-8 weeks
  • Gradual tapering
• Supportive care:
  • Nutritional support
  • Fluid and electrolyte management
  • Pain management
  • Treatment of complications

Monitoring & Follow-up

Clinical Monitoring:

• Weekly first month
• Monthly thereafter
• Parameters:
  • Symptom resolution
  • Weight gain
  • Abdominal girth
  • Treatment adherence

Laboratory Monitoring:

• Monthly:
  • Liver function tests
  • Complete blood count
  • ESR/CRP
• Imaging:
  • Ultrasound at 3-6 months
  • CT scan if needed

Complications

Early Complications:

• Intestinal obstruction
• Perforation
• Malnutrition
• Acute kidney injury

Late Complications:

• Adhesions
• Sclerosing peritonitis
• Short bowel syndrome
• Chronic malabsorption

Special Scenarios

HIV Co-infection:

• Higher mortality
• Atypical presentation
• Drug interactions
• Longer treatment duration

Drug Resistance:

• MDR-TB management
• Alternative drug regimens
• Extended treatment duration
• Close monitoring

Prognosis Factors:

• Early diagnosis
• Nutritional status
• Immune status
• Complications