Which of the following is a sign that may indicate catheter-related tunnel infection?

• A. Redness at the exit site only
• B. Fever with no exit-site signs
• C. Redness and swelling along the subcutaneous tunnel, possibly with fever
• D. Clear drainage at the exit

Answer: (C)

A catheter-related tunnel infection shows inflammation along the subcutaneous tunnel that the catheter travels through, not just at the skin exit. Redness and swelling along that tunnel, and sometimes fever, reflect infection spreading along the path under the skin from the exit toward the abdomen. This distinguishes it from an exit-site infection, which would present as redness or irritation confined to the skin where the catheter leaves the body. Fever with no exit-site signs could indicate a systemic infection, but it doesn’t specifically point to a tunnel infection. Clear drainage at the exit is not typical of an infectious process. Therefore, redness and swelling along the subcutaneous tunnel, possibly with fever, best indicates a tunnel infection. Prompt recognition and medical evaluation are important to control the infection and protect the catheter.