The nurse is assessing a client's skin and notices a raised nodule on the right forearm that is tender and filled with purulent secretions. The healthcare provider diagnosed the abscess as a furuncle. Which pathological etiology places the client at risk for the development of a furuncle?

A. Enzyme immunoassay. The enzyme immunoassay (EIA), also known as the ELISA test, is used as a primary screening test for HIV. If the EIA test is positive, a confirmatory test, such as the Western Blot, is performed to ensure accuracy.

B. Western Blot. The Western Blot is a confirmatory test for HIV used to verify positive results from an initial screening test. It detects specific HIV antibodies and is highly specific, reducing the likelihood of false positives.

C. White blood cell differential. A white blood cell (WBC) differential assesses the overall immune response but does not diagnose HIV. While some HIV patients may show low WBC counts, this test is not specific for HIV infection.

D. CD4+ cell count. CD4+ cell count is used to monitor disease progression and immune function in HIV-positive patients, but it is not a confirmatory test for diagnosing HIV. A low CD4+ count suggests HIV progression toward AIDS rather than initial diagnosis.

A. Increase in interstitial osmotic pressure due to cellular damage. A crushing injury damages cells, leading to the release of intracellular proteins and solutes into the interstitial space. This increases interstitial osmotic pressure, drawing fluid from the blood vessels into the injured tissues, causing edema. The inflammatory response further contributes to capillary permeability and fluid leakage.
B. Decrease in interstitial pressures due to low blood pressure. Blood pressure does not directly regulate interstitial pressure in a localized trauma area. Even if systemic blood pressure were low, localized edema can still occur due to tissue damage and increased capillary permeability.
C. Increased intravascular osmotic pressure due to crushing injury. Osmotic pressure in the blood is primarily determined by plasma proteins, such as albumin. A crushing injury does not increase intravascular osmotic pressure; instead, it increases interstitial osmotic pressure, pulling fluid out of the blood vessels.
D. Increased intravascular hydrostatic pressure due to trauma. While trauma can cause localized vascular changes, hydrostatic pressure primarily affects systemic circulation. In this case, localized tissue damage and inflammation—not increased intravascular pressure—are responsible for edema formation.