What are the symptoms and treatment of abdominal tuberculosis (TB)?

Abdominal Tuberculosis: Symptoms and Treatment

Abdominal tuberculosis presents with nonspecific symptoms—most commonly fever (70-84%), abdominal pain (65-88%), and weight loss (36-68%)—and should be treated with a standard 6-month anti-tuberculosis regimen consisting of isoniazid, rifampin, pyrazinamide, and ethambutol in the initial 2-month phase, followed by isoniazid and rifampin for 4 months. 1, 2, 3

Clinical Presentation

Cardinal Symptoms

The symptom triad that should raise suspicion includes:

• Fever (70-84% of cases), often accompanied by night sweats (30-50%) 1, 4, 2, 3
• Abdominal pain (65-88% of cases), typically nonspecific in character 1, 4, 2, 3
• Weight loss (36-68% of cases), often significant and progressive 1, 4, 2, 3

Additional Common Manifestations

• Vomiting (43%) and abdominal distension (37-67%) 4, 3
• Altered bowel habits: diarrhea or constipation (27-39%) 4, 3
• Anorexia (30-50%) 4, 2
• Palpable abdominal mass (13-26%), particularly in the right lower quadrant 4, 2, 3
• Ascites (30-67% of cases), which may be free or loculated 1, 2, 3

Physical Examination Findings

• Fever on examination (73%) 3
• Ascites (61%) 3
• Cachexia (75%) and anemia (77%) 2
• Features of intestinal obstruction (9%) in advanced cases 2

Anatomical Distribution

The ileocecal region and terminal ileum are involved in 50-90% of gastrointestinal TB cases, making this the most critical area to evaluate. 1, 5

Site-Specific Involvement

• Intestinal TB (58-60% of abdominal TB cases), predominantly ileocecal 1, 5, 2
• Peritoneal TB (most common form of abdominal TB overall), involving peritoneum, mesentery, and omentum 1
• Disseminated abdominal TB (38%) with multiple site involvement 2
• Solid organ involvement (10%), particularly liver and spleen (70% of solid organ cases) 1

Diagnostic Considerations

High-Risk Populations Requiring Heightened Suspicion

• Immigrants from endemic areas (Asia, Africa) 1, 5, 6
• HIV/AIDS patients and other immunocompromised individuals 1, 5
• Patients on immunosuppressive therapy 1
• History of pulmonary TB (present in 18-30% of cases) 4, 2, 3

Critical Diagnostic Pitfalls

The presentation mimics Crohn's disease, malignancy, and other inflammatory conditions, leading to diagnostic delays in the majority of cases. 1, 7, 6 Night sweats and positive tuberculin skin test favor TB over Crohn's disease, though the tuberculin test is positive in only 27% of cases. 5, 3

Up to 85% of patients with abdominal TB have no pulmonary involvement, so absence of lung disease does not exclude the diagnosis. 1

Imaging Findings

• CT scan abnormalities (80% of cases): ascites, peritoneal lesions, enlarged lymph nodes with peripheral enhancement and central hypodensity 1, 3
• Mesenteric lymphadenopathy (23%) with characteristic necrotic centers 1
• Lipohydric level in ascites with necrotic lymph nodes is highly specific for tuberculous ascites 1

Complications Requiring Surgical Intervention

Major Complications

• Intestinal obstruction due to strictures (single in 25%, multiple in 22%) or ileocecal narrowing 1, 5, 4
• Perforation in ulcerative-type TB (10% of cases) 1, 5, 4

When perforation occurs, resection and anastomosis is superior to primary closure and should be the treatment of choice. 1

Medical Treatment

Standard Regimen

A 6-month regimen is adequate for peritoneal and intestinal tuberculosis. 1

Initial Phase (2 months):

• Isoniazid 1, 8, 9
• Rifampin 1, 8
• Pyrazinamide 1, 8
• Ethambutol (add as fourth drug unless INH resistance rate is documented <4%) 1, 8

Continuation Phase (4 months):

• Isoniazid and rifampin 1, 8, 9

Dosing Specifics

Adults: Isoniazid 300 mg daily, Rifampin per standard tuberculosis dosing 9, 8

Children: Isoniazid 10 mg/kg (up to 300 mg daily) 9

Streptomycin (when added for suspected drug resistance): Adults 15 mg/kg daily (max 1 g), Children 20-40 mg/kg daily (max 1 g) 10

Treatment Duration Considerations

Treatment should be continued for longer than 6 months if the patient remains culture-positive, has resistant organisms, or is HIV-positive. 8

Total streptomycin dose should not exceed 120 g over the course of therapy, and reduced dosing is required in patients >60 years due to toxicity risk. 10

Adjunctive Corticosteroids

Corticosteroids should NOT be prescribed routinely for tuberculous peritonitis, as data supporting their use are limited. 1

Surgical Management

Indications for Surgery

Surgery is required in a minority of cases but becomes necessary for: 7, 2, 6

• Perforation
• Intestinal obstruction not responding to medical therapy
• Diagnostic uncertainty requiring tissue diagnosis
• Complications such as fistula formation

Surgical Procedures

• Resection and anastomosis (40% of surgical cases)—preferred for perforation 1, 4
• Right hemicolectomy (37% of surgical cases) for ileocecal disease 4
• Stricturoplasty (13% of surgical cases) for strictures 4
• Ileostomy (3% of surgical cases) as life-saving measure in severe cases 1, 4

Treatment Outcomes

Most patients (96%) respond well to standard anti-tuberculosis therapy when diagnosed early and treated appropriately. 2, 3 Mortality is primarily related to diagnostic delays leading to complications such as perforation or severe malnutrition. 6, 3

Prompt initiation of anti-TB medications after surgical intervention is critical for successful outcomes. 6