The healing process: How the body responds to scrapes and cuts

"When you get a cut, how does the body heal? How does your skin heal?" asked fifth-graders in Elise Diaz and Caroline Dicentio's classes at Prairie Trail School in Gurnee.

Scraped knees, fingers with paper cuts. Almost daily our bodies experience some sort of slight wound.

Your body is equipped with a resilient healing process, and an injury triggers a quick response.

"The first step is that the body tries to limit blood loss," explained Dr. Anthony J. Mancini, head of the Division of Dermatology at Ann & Robert H. Lurie Children's Hospital of Chicago, and professor of Pediatrics and Dermatology at Northwestern University Feinberg School of Medicine. "Proteins in the blood, such as fibrin, and platelets - a type of blood cell - create a clot and make a protective covering, a scab or crust. All of this goes into play within seconds."

The reaction to a cut or scrape is immediate, but complete healing for a more significant wound takes as long as one to two years.

"By three months, a healed wound has around 60 (percent) to 70 percent of the strength of the original skin, and it's not as strong," Mancini said. "Fortunately, children tend to heal beautifully and have a more robust and effective healing response. As you get older, it's easier to bruise, you have 'thinner' skin, and wounds take longer to heal."

In the next phase of the healing process, the body generates granulation tissue to help regenerate the skin and also sends to the site macrophages - a type of white blood cell - that play a role in helping to prevent infection.

"Such cells release growth factors, which further help to repair the wound. There is oxygen delivery to the area from red blood cells, which is very important for proper healing. Eventually, new collagen, another protein, is produced and forms a scaffolding for the repair process. With deeper wounds, a scar eventually develops."

Mancini offers advice on how patients can help along the healing process and minimize scarring.

"In the short-term, we want to prevent infection," he said. "Gentle washing with soap and water is recommended. Sun avoidance is also helpful in promoting healing and preventing pigmentary changes in the skin. With larger wounds that are healing with scarring, gentle massage a few times daily may help minimize the extent of the scar."

How do you know if your cut should be managed at home or by a physician?

"A wound that won't stop bleeding after five to 10 minutes of firm pressure, as well as larger or deeper wounds, require a doctor's attention. If a parent has a question, especially with any significant wound on the face, they should call their doctor or visit an emergency room," Mancini said. "If bleeding is significant, call 911."

Should you cover the wound or leave it open to the air?

"Studies suggest that it's best to keep wounds covered for at least five to seven days to promote better healing; wounds left uncovered become dry and this may impede the healing response," he said. "However, some oxygen delivery is optimal, so avoid overly-constrictive dressings or membranes."

When care includes the use of over-the-counter antibacterial ointments, watch for signs of allergic contact dermatitis.

"Increasing redness and marked itch may suggest an allergic reaction to a topical product. The most common offenders are neomycin and bacitracin," Mancini said. He recommends the use of a petroleum jelly-based ointment, such as Vaseline or Aquaphor healing ointment, which help to keep the wound moist and carry a very low risk of contact reactions.

Check it out

The Warren-Newport Public Library suggests these titles on skin and wound healing:

• "The Amazing Human Body: Skin" by Lorrie Klosterman

• "Taking Care of My Skin" by Terri DeGezelle

• "Everything You Wanted to Know About the Human Body" by Dr. Patricia Macnair

• "Inside Human Body" by Dr. Aron Bruhn, M.D.

• "Cells" by Kimberly Fekany Lee