Hematologic, Immunologic, and Neoplastic Disorders Practice Test

Opportunistic infections in a child with immunodeficiency point to a problem with T-cell–mediated immunity, most concerning for HIV infection progressing toward AIDS. HIV damages CD4+ T cells, weakening defenses against organisms like Candida, so oral thrush becomes more frequent and severe. In an older child, this pattern of immune weakness with a fungal infection is a classic red flag for AIDS.

Hemophilia is a coagulation disorder that explains bleeding risk, not immune suppression or fungal overgrowth. Iron deficiency anemia and lead poisoning cause anemia and other systemic issues but do not account for an underlying immunodeficiency with opportunistic infection in this context.