Radiographic studies aid greatly in the diagnosis of extrapulmonary tuberculosis in children. Plain radiographs, CT, and magnetic resonance imaging (MRI) of the tuberculous spine usually show collapse and destruction of the vertebral body with narrowing of the involved disk spaces. Radiographic findings in bone and joint tuberculosis range from mild joint effusions and small lytic lesions to massive destruction of the bone.
In tuberculosis of the CNS, CT or MRI of the brains of patients with tuberculous meningitis may be normal during early stages of the infection. As disease progresses, basilar enhancement and communicating hydrocephalus with signs of cerebral edema or early focal ischemia are the most common findings.
The differential diagnosis of tuberculosis includes a multitude of diagnoses because tuberculosis may affect any organ, and in early disease the symptoms and signs may be nonspecific. In pulmonary disease, tuberculosis may appear similar to pneumonia, malignancy, and any systemic disease in which generalized lymphadenopathy occurs. The diagnosis of tuberculosis should be suspected if the TST or IGRA is positive or if there is history of tuberculosis in a close contact.
The differential diagnosis of tuberculous lymphadenopathy includes infections caused by atypical mycobacteria, cat-scratch disease, fungal infection, viral or bacterial disease, toxoplasmosis, sarcoidosis, drug reactions, and malignancy. The diagnosis may be confirmed by fine-needle aspiration but may necessitate excisional biopsy accompanied by appropriate histologic and microbiologic studies.
The treatment of tuberculosis is affected by the presence of naturally occurring drug-resistant organisms in large bacterial populations, even before therapy is initiated, and the fact that mycobacteria replicate slowly and can remain dormant in the body for prolonged periods. Although a population of bacilli as a whole may be considered drug susceptible, a subpopulation of drug-resistant organisms occurs at fairly predictable frequencies of 105 to 107, depending on the drug. Cavities may contain 109 tubercle bacilli with thousands of organisms resistant to any one drug, but only rare organisms are resistant to multiple drugs.
Patients with latent tuberculosis infection have small bacterial populations and a single drug, such as isoniazid, can be
Table 124-3 Recommended Treatment Regimens for Drug-Susceptible Tuberculosis in Infants, Children, and Adolescents INFECTION OR DISEASE CATEGORY REGIMEN COMMENTS LATENT TUBERCULOSIS INFECTION (POSITIVE TST RESULT, NO DISEASE)
Isoniazid-susceptible 9 months of isoniazid, once a day If daily therapy is not possible, DOT twice a week can be used for 9 months.
Isoniazid-resistant 6 months of rifampin, once a day
Isoniazid-rifampin–resistant Consult a tuberculosis specialist.
If hilar lymphadenopathy only, a 6-month course of isoniazid and rifampin is sufficient.
Drugs can be given 2 or 3 times per week under DOT in the initial phase if nonadherence is likely.
rifampin, once a day or twice a week For patients who may have acquired tuberculosis in (9–12 months total) geographic areas where resistance to streptomycin is common, capreomycin, kanamycin, or amikacin may be used instead of streptomycin.
Recommendations from Pickering LK, Baker CJ, Long SS, et al: Red Book: 2012 Report of the Committee on Infectious Diseases, ed 27, Elk Grove Village, IL, 2012,
American Academy of Pediatrics. DOT, Directly observed therapy; TST, tuberculin skin test.