Which of the following is NOT among the three common signs of infection that trigger isolation precautions?

• A. Fever
• B. Purulent drainage
• C. Elevated white blood cell count
• D. Rash

Answer: (D)

Infection control relies on signs that indicate an infectious process that could be spread to others. Fever, purulent drainage, and an elevated white blood cell count are the three common indicators clinicians look for because they reflect systemic or localized infection and an active immune response: fever shows the body fighting infection, purulent drainage signals an infected site, and a high WBC count indicates the body’s defense is activated. A rash, while it can occur with some infections, is not a universal or reliable trigger for isolation precautions since many noninfectious conditions also cause rashes, and not all infections present with a rash. So rash is not among the standard signs used to initiate isolation precautions.