Although the lung is the most common organ to be infected by TB bacilli, tuberculosis can involve any other organ of the body (extrapulmonary tuberculosis). The organs which are most commonly infected via the blood stream in children are:
- The meninges (tuberculous meningitis)
- Bones, especially the spine (tuberculous osteitis)
- Joints, especially the hip joint (tuberculous arthritis)
The abdomen, skin, tonsils, pericardium, bone marrow, middle ear and genitalia are less common sites of tuberculosis in children. Tuberculosis of the kidney usually only follows 5 or more years after the primary infection and therefore is uncommon in childhood.