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112 Tuberculosis

• hematogenous spread from reactivation of old primary lung focus; tool when tuberculosis cannot be excluded by radiology or specific
tuberculin skin tests (TSTs). Thoracotomy and excision are reported as
• ingestion of infected sputum from active pulmonary focus;
necessary to treat the obstructive symptoms. Thoracoscopic mediastinal
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• contiguous spread from adjacent organs; and node biopsy has also been reported as feasible in an infant. Infants
<6 months of age may present with respiratory failure, requiring
• through lymph channels from infected nodes.
ventilatory support.
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The most common site is the terminal ileum and ileocaecal region
Extrapulmonary TB includes peripheral lymphadenopathy,
due to increased physiological stasis, increased fluid and electrolyte
tubercular meningitis, miliary TB, skeletal TB, and other organ
absorption, minimal digestive activity, and an abundance of lymphoid
involvement. Any child with pneumonia, pleural effusion, or a cavitary
tissue at this site. The other sites, in order of frequency, include the
or mass lesion in the lung that does not improve with standard
colon and jejunum. Rarely, tuberculosis may involve other areas such
antibacterial therapy should be evaluated for tuberculosis.
as the perianal region, appendix, duodenum, stomach, and oesophagus.
The clinical presentation of abdominal tuberculosis can be acute,
The nodal involvement due to tuberculosis is commonly mesenteric
chronic, or acute on chronic. Most patients have constitutional
or retroperitoneal. The abdominal solid organs (liver, spleen, and
symptoms of low- or high-grade fever (40–70%), weight loss (40–90%),
pancreas) may also be affected with tuberculosis, but rarely.
night sweats, anorexia, and malaise. The delay in presentation can vary
Pathophysiology between 1 and 14 months. Abdominal symptoms include diarrhoea,
Nearly all cases of abdominal TB are due to the human strain of M. constipation, alternating constipation and diarrhoea, and pain, which
tuberculosis, although atypical mycobacteria account for a few cases. can be either colicky due to luminal compromise or dull and continuous
Infection due to the bovis species is rare, largely due to the practice of when the mesenteric lymph nodes are involved. A physical examination
boiling milk. In India, the organism isolated from all intestinal lesions may show features of ascites, lump abdomen, or visible peristalsis with
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has been M. tuberculosis and not M. bovis. The peritoneum is com- dilated bowel loops. Miliary tuberculosis presenting with multiple
monly involved, although any part of the abdominal cavity, such as intestinal perforations as an initial manifestation of the disease has also
hollow viscera, lymph nodes, and solid viscera, may be involved. An been reported in an infant. 13
accurate diagnosis requires a high index of suspicion, as most of the Tuberculosis of the Abdomen
investigations are nonspecific and less sensitive. Any part of the abdomen may get involved in tubercular pathology.
Tuberculous granulomas of variable size are initially formed in The chronic intestinal lesions produced by tuberculosis are of three
the submucosa or the Peyer’s patches. Tubercular ulcers are relatively types: ulcerative, hypertrophic, and stricturous. The ulcerative form
superficial, transversely oriented, and do not penetrate beyond the is seen more often in malnourished patients, whereas the hypertrophic
muscularis. Cicatrical healing of these circumferential ulcers results form is seen in relatively well-nourished patients. Colonic and ileo-
in strictures. Mesenteric lymph nodes may be enlarged or matted, and caecal lesions are ulcerohypertrophic. In tuberculous peritonitis, the
may caseate. gross pathology is characterised by omental thickening and peritoneal
A cell-mediated immune response terminates the unimpeded growth tubercles. 14,17,18
of M. tuberculosis within 2 to 3 weeks after the initial infection. Cluster Peritoneal Tuberculosis
of differentiation 4 (CD4) helper T cells activate the macrophages
to kill the intracellular bacteria with resultant epithelioid granuloma Peritoneal tuberculosis occurs in four forms:
formation. CD8 suppressor T cells lyse the macrophages infected with 1. Wet type peritonitis with generalised ascitis: The distended abdomen
the mycobacteria, resulting in the formation of caseating granulomas. is in sharp contrast to that of a malnourished child, with little muscle
Mycobacteria cannot continue to grow in the acidic extracellular mass and subcutaneous fat.
environment, and thus most infections are controlled. The only 2. Encysted (loculated) ascitis type: The child may present with an
evidence of infection is a positive tuberculin skin (Montoux) test result. asymptomatic localised abdominal lump, which may be due to loculated
Clinical Presentation ascites, enlarged lymph node, or matted omentum and intestines.
Tuberculosis patients are usually malnourished, as they belong to lower 3. Dry type with adhesions: The child presents with subacute abdominal
socioeconomic strata. Primary pulmonary tuberculosis may present obstruction or a history of feeling a moving ball of wind abdominally.
with generalised symptoms, such as fever of unknown origin, failure 4. Classic “plastic” form: This is a fibrotic type with abdominal
to thrive, night sweats, anorexia, significant weight loss, nonproduc- masses composed of mesenteric and omental thickening, with
tive cough, or unexplained lymphadenopathy. Pulmonary TB may matted bowel loops felt as lump(s) in the abdomen. The adolescent
manifest as endobronchial TB with focal lymphadenopathy, progressive has gastrointestinal (GI) symptoms along with a doughy feel of the
pulmonary disease, pleural involvement, and reactivated pulmonary abdomen. The latter is due to diffuse peritonitis with thickening
disease. Progression of the pulmonary parenchymal infection leads to and adhesions of omentum, mesentery, and peritoneum. The
enlargement of the caseous area and may lead to pneumonia, atelec- classic presentation is, however, with attacks of subacute intestinal
tasis, and air trapping in young children. Children usually appear ill obstruction, most of which resolve on conservative management. A
with symptoms of fever, cough, malaise, and weight loss. Tubercular lump is found in 25–33% of cases, most often in the right iliac fossa,
pleural effusion may present with acute onset of fever, chest pain that in ileocaecal and small bowel TB.
increases in intensity on deep inspiration, and shortness of breath. Fever A combination of these types is also common. Tubercular peritonitis
usually persists for 14–21 days. Reactivation TB usually has a subacute and nodal forms are more commonly seen in children and adolescents
presentation with weight loss, fever, cough, and, rarely, haemoptysis. as compared to the gastrointestinal form.
Reactivation TB typically occurs in older children and adolescents. Mesenteric and other lymphadenitis
Isolated mediastinal tuberculous lymphadenitis is a relatively
Nodal forms can present as a lump or intestinal obstruction due to kinks
common entity in children, second in frequency after cervical
and adhesions. Bowel loops may get involved in the inflammatory pro-
localisation. In the absence of an accompanying parenchymal
cess and form a local lump in the right iliac fossa, producing subacute
lesion, mediastinal tuberculous lymphadenitis may pose a diagnostic
obstruction. Obstructions of the bile duct, pancreatic duct, duodenum,
dilemma on admission and must be distinguished from other causes
inferior vena cava, or ureter by lymph nodes may also occur, but are rare.
of mediastinal masses. Bronchoscopy is suggested as a diagnostic