Why Do We Close Skin?

When I ask a medical student or resident, “Why do we close skin?”, he or she usually states, “Well, it’s to prevent the wound from getting infected.”

I then would follow up with “What do we do with an infected wound?” The trainee would the typically respond with, “Well, we open it so the pus can drain out of it.”

So, I respond with “Then why did we close it in the first place?”

At this point the trainee is genuinely flummoxed. There’s a paradox running around in his or her head. If we close a wound to prevent its infection, then why do we open it to treat a wound infection?

I explain that we close a wound for cosmetic reasons. That is, clean wounds are usually closed at the end of the operation. Such a procedure is called closure by primary intention. Primary intention means to close the wound so that it will end up with a less visible scar.

However, in the case of an infected wound, primary intention is not practiced due to the high likelihood of the infection persisting in the tissues and expanding, ultimately requiring surgical drainage.

Instead such cases, the infected wound is left open to be treated with frequent irrigations and the application of absorbent dressings or a negative pressure wound drainage system known as a “wound vac”.

Understanding the nature of wounds, and wound infection is often a paradigm shift for trainees.