Differential Diagnosis for a Bulge at IV Site

• Single Most Likely Diagnosis
  • Phlebitis or IV infiltration: This is the most common cause of a bulge at an IV site, resulting from the IV catheter causing irritation to the vein or leaking fluids into the surrounding tissue.
• Other Likely Diagnoses
  • Hematoma: A collection of blood outside of blood vessels, which can occur if the IV needle punctures the vein or an artery, leading to bleeding into the soft tissues.
  • Abscess: A pocket of pus that can form as a result of infection at the IV site, which may cause swelling and a bulge.
  • Cellulitis: A bacterial skin infection that can cause redness, swelling, and warmth around the IV site, potentially leading to a bulge.
• Do Not Miss Diagnoses
  • Septic thrombophlebitis: An infection of the vein that can lead to a blood clot, which is a serious condition requiring prompt treatment to prevent sepsis and other complications.
  • Necrotizing fasciitis: A rare but life-threatening infection that destroys the tissue under the skin, including fat and the tissue covering the muscles (fascia), which can start at an IV site.
• Rare Diagnoses
  • Pseudoaneurysm: A rare complication where a leakage of arterial blood from the IV site into the surrounding tissue forms a blood-filled sac, which can cause a bulge.
  • Foreign body reaction: Although rare, if a foreign object (like a piece of the IV catheter) is accidentally left in the tissue, it can cause a reaction leading to swelling and a bulge.