Mar 4, 2022


Dr. Tarbox: Hello, and welcome to "Skincast," the podcast for people who want to take the very best care of the skin they're in. My name is Michelle Tarbox, and I'm an Associate Professor of Dermatology and Dermatopathology at Texas Tech University Health Sciences Center in beautiful sunny Lubbock, Texas. And joining me today is . . .

Dr. Johnson: Hey, this is Dr. Luke Johnson. I'm a pediatric dermatologist and general dermatologist with the University of Utah.

Dr. Tarbox: Today, we're going to talk about scars. Luke, what's a scar?

Dr. Johnson: A scar is a part of your skin that you don't like that was probably caused by some kind of process. That's pretty generic. Not everybody dislikes the scars. Maybe you like your scars. Scars are cool.

They're basically some extra collagen fibers that the body has used to try to repair what it perceives as an injury. And my guess is that everybody listening to this probably has at least one scar on their body from something or other.

There are different reasons you can get scars. For example, I'm looking at my hand right now, and I can very faintly make out the scar that I got in high school when one of our friends pushed me into a chain link fence. That would be a traumatic scar.

Dr. Tarbox: Traumatic scars are probably the most common and almost everyone has some experience with traumatic scarring, whether it be from a skinned knee, an unfortunate incident with a chain link fence, or some other kind of skin assault.

Our skin is kind of miraculous, really. It's this miraculous living fabric that can repair itself. And it has a really important job, which is protecting what's inside of us from what's outside of us. So that outside whole integrity is such an important piece that our body has got a very sophisticated wound healing response that can occur in response to multiple different stimuli, one of which being a traumatic wound.

Another kind of scarring that we sometimes see is inflammatory scarring. I think the hallmark of this would be acne scars. So most people also have some experience with acne. When acne gets very inflamed, it can create scarring on the skin that can result in either indented scars or scars that stick out.

Dr. Johnson: Doctors and other such people also like to make scars on people. So if you have something cut out from your skin, for example, like a mole that a dermatologist was worried about, then you're left with a scar afterward.

Dr. Tarbox: And surgical scars can have a sort of special set of circumstances that can optimize their wound healing after the surgical course. So your physician should give you wound care instructions, and you want to follow them carefully to help improve scar cosmesis.

Another cause of scarring is burns. So burns can take the place of thermal burns, such as heat from a fire or potentially a heating pad or blanket that gets turned on and left on too long. They can also take the place of radiation, such as solar radiation. A sunburn, when it's severe, can cause scarring, as can radiation, which is sometimes used therapeutically to treat cancer or other types of problems.

Dr. Johnson: There is a difference between scarring and what dermatologists call post-inflammatory change. So any time the skin is inflamed, whether it's from a dermatologic condition like eczema, for example, or for any other reason, then it can be discolored afterward. It can be a lighter color than the normal skin, or it can be darker. It can also just be pink. So even if it's pink, it doesn't necessarily mean it's currently inflamed. It could have been inflamed, but now it's just pink, which is fading away.

I think most of us have seen this, especially with acne again. So sometimes I'll see patients with acne and I'll look closely and say, "Oh, actually their acne just looks worse than it is because they have all this post-inflammatory change."

The good news about post-inflammatory change is that, unlike scars, it goes away. It can take a long time. It can take months or even a year or two sometimes before it goes away. But the good news is that it will get better.

Dr. Tarbox: I like to tell my patients that the life of the scar starts at the time of injury and its destiny is determined by what you do after that injury.

So how do we minimize scarring? The first thing is, of course, after the time of injury, you want to make sure that the area of wounding is clean and you want to prevent infection. Infection will almost always result in more severe scarring than healthy skin that heals without an infection. So you want to keep the wound clean and you want to make sure that any kind of debris or anything like that if it's a traumatic wound is removed.

Then you want to keep the wound microenvironment moist. The way I like to think about this is if you've ever tried to regrow a grass lawn, you think about how you treated that lawn. So whenever you're trying to regrow a bald patch in a lawn, you're trying to heal the lawn, if you will, then you want to keep that part of the lawn nice and moist so that new grass can sprout up.

And you also don't want to put big blocks of concrete down on that growing grass, like a scab. A scab is actually going to get in the way of your wound healing well, and it will cause a more significant scar. Scabs are not your friends. So a lot of people kind of want to leave the wound open to air and get it to make a nice thick scab. Scabs can be protective in a way that they kind of reinforce the skin barrier. But if you can protect the skin through some other means, such as a bandage and some kind of moisturizing dressing, the wound will heal with less of a significant scar.

Dr. Johnson: One of our favorite moisturizers to put on a wound is plain old Vaseline or petroleum jelly. You've heard it before on this show. You'll hear it again. Aquaphor is okay too. I consider Aquaphor like expensive Vaseline. No offense, Aquaphor. But whatever you like.

So usually for surgical wounds, for example, if we are cutting something out of people's skin, we'll put some Vaseline and a bandage on it after we're done. And then 24 to 48 hours later, we suggest that every day you would take the bandage off, wash the area gently with soap and water and then reapply Vaseline and a Band-Aid.

And you can do the same thing if you are injured or have a scar or a wound for any other reason. Wash gently every day with soap and water, Vaseline, bandage, and that will give you the best chance of having the best-looking scar afterward.

Dr. Tarbox: If the wound is not infected, you really don't need a topical antibiotic ointment. A lot of the benefit from topical antibiotic ointments comes from the fact that they are basically Vaseline plus medicine.

If you do have a superficial skin infection, a topical antibiotic can be beneficial. However, some people are allergic to certain over-the-counter topical antibiotics. I'm one of those people. I'm allergic to Neosporin. If you're allergic to Neosporin, it's also quite likely you're allergic to Polysporin or Bacitracin. Those have a lot of cross-reactive allergies.

And if you have that allergic response, you get itchier and more uncomfortable after you put on that topical product, it might be better just to go back to plain Vaseline.

With Aquaphor, it does have lanolin in it, which is kind of . . . Actually, it's sheep sebum. It's kind of a weird thing that we put that on skin, but our skin has our sebum on it. It's oil secretions from our oil-making glands. What we put in Aquaphor to make it Aquaphor is sheep sebum. So we have sheep sebum plus Vaseline, which is Aquaphor.

Some people really like vitamin E oil. How do you feel about it, Luke?

Dr. Johnson: I am unconvinced that it does anything beyond just moisturize the way Vaseline would.

Dr. Tarbox: And vitamin E oil is one of the other things people can develop an allergy to. A true allergy to Vaseline is almost nonexistent.

Some people will also use silicon sheets. Silicon sheets are very unlikely to cause any kind of allergy and can definitely improve scar cosmesis. They can be purchased over the counter or can be prescribed. And there are also silicon gels that can be used. What about . . .

Dr. Johnson: I also haven't seen convincing data about the silicone sheets, I'll say. We have a different podcast, Michelle, and we discussed a dermatology research article about silicone sheets in women with C-section scars and the women who had a tendency to overgrow scars. So if you have a tendency to develop something called a hypertrophic scar, or a keloid, then the silicone sheets did help. But I don't think they improved the appearance of just sort of average run-of-the-mill scars. So I'm not convinced about those ones either.

Dr. Tarbox: There's a product called Mederma that is sold over the counter as a scar gel to help improve the appearance of scars. It actually is based on an onion extract, Luke. There was a trial that actually compared head-to-head just plain Vaseline versus the Mederma as a topical treatment for scar and hypertrophic scar prevention.

And they did a very sophisticated type of study where they did something called a randomized double-blinded split scar study. So it was a very rigorous study where they put the onion extract gel, which is the Mederma, on one part of the scar and the Vaseline on the other part of the scar. Same patient, same scar, just different treatment for different parts of it. And the onion extract gel did not improve scar cosmesis over the petrolatum, the Vaseline. The result was the same. So you can kind of save your money with that one.

Also, Mederma can cause some skin allergies. I'm actually also a person who happens to be allergic to Mederma.

What other topicals do people use?

Dr. Johnson: People use lots of different things, but I am a believer in Vaseline if that wasn't clear by now. So I don't think that there's a lot of good medical data . . . I'm not saying it definitely doesn't work. I'm just saying that there's not good medical data that says things like essential oils can help, or I've seen people use oregano oils. They smell good and they're moisturizing, so that part can help, but I feel that simpler is better and you want to stick with something pretty plain.

Dr. Tarbox: Yeah. And extra fragrance, extra herbal things can also trigger allergic responses, which can complicate the healing process and actually worsen the scar.

Once the scar is mature, how can people improve the appearance of their scar?

Dr. Johnson: Well, it depends on what you mean by a mature scar, I suppose. I like to tell patients that a scar takes a complete year to fully remodel, and it's at its wimpiest in the first few weeks. It never, ever gets to full strength, but it eventually gets to like 80% of normal skin strength. So I think a month or two after you've been injured, perhaps with a surgery, perhaps with a chain link fence.

You can massage the scar. So there's some medical data that says massaging the scar can help. Do you have recommendations to your patients about that, Michelle?

Dr. Tarbox: I do think scar massage can help in a couple of different ways. One of the ways it can help is just improving circulation to that tissue. Our scar tissue doesn't have as much vascularity to it, actually. It can appear extra red when it's in the acute healing period, but when you look at it under the microscope, the actual density of blood vessels in a mature scar is decreased.

You can also help improve adherence to underlying tissue. So if the wound is deep, you might have more of an indented scar because it gets kind of stuck to the tissue underneath it. And scar massage can help alleviate that.

The way I recommend to do scar massage . . . I like a couple of different things. You can use just plain Vaseline. Some people like castor oil. There's an over-the-counter product called Bio-Oil that I like for scar massage. But I like for patients to take the scar between their fingers and kind of roll the scar and pull it up away from the underlying tissue to help give better movement and decrease any kind bound-down appearance.

Dr. Johnson: When do you have them start using the massage, and for how long, and how many times a day, and for how many weeks, and all that kind of stuff?

Dr. Tarbox: So once the scar is kind of done with the acute healing process, about four to six weeks in, I have people start to do scar massage. I don't want them to do it too early after the initial wound is placed because I don't want the wound to get opened back up. We call that dehiscence of a wound, and that gives a more complicated healing process to the skin. So about six weeks out, I'd have them start to do the scar massage.

I like for them to do it for about five minutes at a time, and at least two to three times daily, if possible. And this can be continued up to, I think, three to six months, depending on the patient's preference.

There's no evidence that scar massage after the acute wound healing period causes any damage to a scar. So it's not possible, I don't think, to hurt yourself with scar massage.

If you have a really bound-down scar, you can actually use those little silicon suction cups to help kind of improve the movement of the tissue and kind of pull it up away from the tissues it might be bound down to.

What other kinds of things impact scars, Luke? What other kinds of habits might impact?

Dr. Johnson: Having sunlight shine on it and smoking. So dermatologists are pretty suspicious of the sun across all aspects of the human body. And it can sort of pigment the scar, especially if your scar is already a little bit pigmented. The sunlight can kind of fix that pigment in place. So especially while your skin is healing, you want to protect it from the sun.

And then smoking is bad for all kinds of reasons, but it reduces blood flow, especially to the smallest blood vessels in the body, which are responsible for delivering nutrients to some of the cells that are working on repairing that scar. And if those cells aren't healthy and working just as well as they could, then the scar is also not going to look so good.

Dr. Tarbox: And what else can be done after all of these processes to help with the appearance of a scar? Let's say they've done all the right things. They didn't smoke, they protected it from the sun, they moisturized the wound, they did their scar massage, but they're still not entirely happy with it. What can we do?

Dr. Johnson: Right. So what if you had a chain-link-fence-related injury in high school and you hate the scar?

Dr. Tarbox: Hypothetically.

Dr. Johnson: What can a dermatologist or somebody else do for you? So one thing we can do is cut the scar out and replace it with a different scar. But this new scar will be done in a more controlled fashion, so perhaps it will be better.

Dermatologists can also use laser treatments on the scars. There are different types of lasers. Some of them are good for the pink color that some scars get. Some of them are good for the texture to kind of help the scar blend in with the surrounding skin.

Unfortunately, there's nothing we can do to just make the scar kind of go away and look like normal skin, but they can still be improved significantly. And acne scars in particular, there's some medical data that says that different types of lasers and then a technique called micro-needling can lead to significant improvement.

Dr. Tarbox: We can also, if we have a very thick scar, potentially inject some steroids into it to help flatten the scar down. Especially if you're dealing with a hypertrophic scar or a keloid, that might be a mechanism that we use to improve the scar's appearance.

If it's more that the edges are very visible, we might do something called dermabrasion, which is kind of like sanding the skin in a technical way. And that's to try to give the skin sort of a chance to re-heal itself.

What about topical things we do?

Dr. Johnson: Well, I think most topical things, unfortunately, don't work once a scar is mature unless, and I don't know why this is true, they're acne scars. So there's a type of medicine called retinoids. We've talked about them before. The prescription versions are tretinoin and tazarotene. They're also available over the counter as products that contain retinol or retinoic acid. And then there's a product called adapalene. The brand name is Differin.

And for some reason, acne scars seem to respond to those, but other types of scars don't. Maybe someday somebody will figure out why, or they'll find that they do work for other types of scars under some particular circumstance. But if it's acne scars that are bothering you, I think you should be using a retinoid unless you're pregnant or breastfeeding.

Dr. Tarbox: Good point. If you've got a scar that you really just don't like the appearance of, and these modalities have been tried, with a physician you may decide to go through what's called scar revision surgery, where the original unsatisfactory scar is removed and another wound is placed in its stead to try to give a second chance to a better opportunity for wound healing. When that happens, it needs to be done carefully by somebody who's an expert at scar revision so that you end up better off rather than worse off.

Dr. Johnson: Well, that's all we've got on scars. I hope you're all "scarry"-eyed after this discussion. Thanks for hanging out with us. Thanks to our institutions. Thanks to the University of Utah for supporting the podcast, and thanks to Texas Tech for lending us Michelle.

If you like hearing us talk, you might want to listen to that other podcast that we make, because I like hearing us talk. Michelle, you want to tell them about "Dermasphere"?

Dr. Tarbox: Our other podcast is called "Dermasphere." It is the podcast for the dermatologists. It's actually the podcast by dermatologists for dermatologists and for the dermatologically curious. It's a longer podcast. Each episode is about an hour, and we review scientific articles that discuss the treatment of dermatologic diseases.

Dr. Johnson: Check it out if you are so inclined, and thanks so much for hanging out with us today. We'll see you next time.