Hematogenous TB develops from primary TB or can be caused by the breakdown of other TB caseous foci into the blood stream. Acute cornified tuberculosis is part of acute systemic hematogenous tuberculosis. It has an acute onset with systemic toxicity and is often associated with tuberculous meningitis. x-rays show corn-like lesions in the lungs, evenly scattered in both lungs, but not obvious under fluoroscopy. When tuberculosis bacilli enter the lungs in small batches, subacute or chronic disseminated pulmonary tuberculosis is formed, and x-ray shows unevenly sized, old and new, symmetrically distributed in the upper middle of both lungs. Blood-borne tuberculosis is the result of blood-borne dissemination of Mycobacterium tuberculosis. It is most commonly seen in children and can also occur in adults. There are two clinical types: (1) acute disseminated pulmonary tuberculosis or acute cornified pulmonary tuberculosis; and (2) subacute or chronic disseminated pulmonary tuberculosis. The most common type of tuberculosis in the pediatric population is acute cornified tuberculosis; older children often present with subacute or chronic disseminated tuberculosis. Therefore, dry heat sterilization requires high temperature and long duration. Tuberculosis bacteria in sputum are killed in direct sunlight within 2 h, while ultraviolet light takes only 10 min. On the contrary, they can survive in the shade for months, and TB bacteria in sputum need 24 h to be effective if disinfected with 5% carbolic acid (phenol) or 20% bleach solution. Mycobacterium tuberculosis does not produce endotoxins or exotoxins. Its pathogenicity may be related to the inflammation caused by the multiplication of bacteria in tissue cells, the toxicity of the bacteriophage components and metabolites, and the immune damage caused by the organism to the bacteriophage components.