What criterion for TB severity is associated with immunocompromised children?

The criterion for tuberculosis (TB) severity that is associated with immunocompromised children is characterized by an induration of 5 mm. For individuals who are immunocompromised, including children, a smaller induration is clinically significant and indicative of active TB or latent infection. This is because their immune responses are not as robust as those of immunocompetent individuals, making them more vulnerable to TB infections even at reduced thresholds.

In the general population, induration of 10 mm is often considered significant for diagnosis, but for immunocompromised individuals, such as those living with HIV or other conditions affecting immune function, an induration of just 5 mm can signal a need for further evaluation and treatment. This criterion is an important part of TB screening in high-risk populations to allow for early detection and intervention.

Other options, while they may indicate the presence of TB, do not directly relate to the specific immunological response expected in immunocompromised children. Cavities visible on radiography and extrapulmonary symptoms signify more advanced disease but are not part of the definitive diagnostic threshold based on induration.