Interview with Dr. David Armstrong: Foot Care, Cracked Heels and Diabetes

David G. Armstrong, Professor of Surgery and Director of the Southwestern Academic Limb Salvage Alliance (SALSA) at Keck Medicine of University of Southern California.

David G. Armstrong, Professor of Surgery and Director of the Southwestern Academic Limb Salvage Alliance (SALSA) at Keck Medicine of University of Southern California.

Q: Tell us a little bit about yourself, your background, and why you chose your specialty?

A: Well, guess you could say I was born into this. My father was a foot doctor, the smartest guy I ever knew. I kind of grew up in the office and clinic. Then when it came time to choose, I went through so many different ideas about what I wanted to do. But I kind of alighted on this area, this humble little specialty in podiatry, because first of all, I just loved it. I saw from my father how someone could walk into your clinic hurting and then walk out the same day feeling better. I thought that was really great. It appealed to my desire for instant gratification. But it's funny that I've gone from that instant gratification to something completely the opposite. Now, I'm looking after the folks with diabetes, with tissue repair and wound healing, where, sometimes success is measured in millimeters and a lot of patients don't have the “gift of pain”. 

Q: In one of your articles or interviews I was reading, you were talking about foot care and humility, and how in every religion it’s actually a very humble position. And I was struck by how true that is.

A: It's an expression of humility, just looking after someone's feet and tending to them. And it's pretty cool because, you know, I'm a professor of surgery here at USC, and surgery is thought to be kind of a ‘high octane’ specialty.  But all my best friends here and throughout medicine and surgery who are good at what they do, and that I want to emulate - they lead with humility. Podiatry in many ways is great because you start from that position.

The other thing about the foot is that it sits right at the end of the body, so it gives you that perspective and forces you to collaborate with the anatomic mainland, as we say.

Q: How does the skin on your foot differ from on the rest of your body?

A: Your foot really is unique in so many ways and it's just beautiful in its complexity. It looks relatively simple, but 20% of your bones are down there!   Your skin is no less specialized, especially on the bottom of the foot. 

There's something called glabrous skin on the bottom of the foot, which really just means that it's specialized in its thickness, and the fat right under that area is also highly specialized.  It's made in an even more advanced sense than the next-generation set of sneakers or kicks that you're wearing. If you look at the insole, the fat down there does the same thing in spreading force out over time and over a large area. It's fascinating to watch that work and we can learn a lot from just looking at the skin, and looking at the underlying structures and the fat and how it's able to absorb so much, for the thousands and thousands of steps you take every day.

Q: What are some of the most common skin issues or conditions that you see and treat on the foot?

A: We see many foot conditions and they are very similar to those that you can find all over the body.  The main difference with issues on our feet  is that often people ignore them because a) they are covered by a sock and a shoe and b) you think it's just going to go away. 

Many of the problems we see on the foot are caused by very common issues, one great example is dry skin which is an eminently treatable condition. Simple things like calluses which happen from just repetitive stress, or cracked heels can lead to more complicated issues. It’s largely when we ignore our feet that we start to have problems. 

When it comes to the foot and diabetes the risk of complications skyrockets. People with diabetes often lose what one of my old mentors used to call “the gift of pain” over a period of time. They can wear a hole in their foot – like you and I would wear a hole in a shoe or a sock – and that hole is called an ulcer, a diabetic foot ulcer. And those happen now every one second around the world. 

Q: Do wounds take longer to heal on your feet than other areas of your body?

A: That's a great question. The answer is yes, quite literally, because it's farther away from your heart. The blood flow to your foot is very different from that going to your head or in your neck, which is kind of programmed to heal. The foot is much like the end of a peninsula.

So when we're, for instance, reconstructing a foot or doing surgery on a foot, we usually leave the sutures a little longer than you would say on the face or on other parts of the trunk or things, because it tends to take a bit longer to heal.


Q: You have talked about a ‘silent sinister syndrome’ in relation to diabetes and foot care. Can you explain a little why you refer to it in these terms?

A: Diabetes by itself is kind of a silent problem. But the most common problem leading to hospitalization is not a heart attack or a stroke, or high blood sugar or even low blood sugar, it's actually a foot complication. 

Of the 37 million people with diabetes now in the United States, about half at any given time are going to have what we call some loss of protective sensation, they’re going to have some neuropathy. And that is the silent sinister syndrome because people literally wear a hole in their foot, as I mentioned earlier, and about half of those wounds are going to get infected. Once that happens, about 1 in 5 of those folks are going to be hospitalized. That’s why there’s an amputation now, every 20 seconds around the world - and every 20 seconds, that’s a tragedy.

You know, we're really good as human beings at reacting and rallying around emergencies. When terrible things happen, we go to help. Or if we hear a noise, we turn to look and we react. But what we don't do really well is react to slow, long term, kind of quiet calamities. Of all these slow moving calamities, changes in the climate, changes in public health and noncommunicable diseases - diabetes is one of the quietest and the most humble of all.

I think that if you were an evil deity and looking for a way to sock it to humanity, you would not pick something boisterous. You would choose something silent and sinister. There certainly isn’t a more silent and sinister syndrome than diabetes. People develop this problem quietly and then they slowly die quietly and it is rarely because of diabetes specifically but rather because of some secondary cause. That stinks. And I think collectively as a family, we can do a lot more about it.

Q: I saw a poster titled “Time is Tissue” and I thought that was so brilliant. Can you speak a little about the importance of having any lesions seen by a medical team if you are diabetic?

A: Time really is Tissue with diabetic foot ulcers!

For a patient with diabetes, days or weeks may mean the difference in saving that toe, foot, leg, or life. These patients cannot afford to fall through the cracks, but often they have significant complications before ever bringing the problem to a health care provider.

The sooner you get to a specialist, the sooner she or he can assess and treat you - which not only improves your chances for healing, but the risk goes down for terrible things like hospitalizations and amputations. 

Q: What do you recommend for good daily foot care? Any do’s and don’ts, or a checklist?

A: Look at your feet!   If you're looking at your feet every day, you will notice if something is different than what it was the day before. It might be just some redness or some swelling that was unusual, cracked heels or maybe a little callus that's showing up, or even an ingrown nail, really anything that was just unusual. You might even find something in your shoe that wasn't there before that might be poking you. 

It’s pretty straightforward. And if you just work it into your schedule, like brushing your hair or your teeth, it can make a huge difference. 

Q: What are the stages of wound healing, and can you describe what is happening in each of these stages?

A: Normal wound healing goes through a beautiful kind of orchestra or symphony, as it were, of steps. 

You have an initial inflammatory reaction which calls in all of these very different kinds of cells, and they are highly orchestrated and communicate with one another. 

These cells can change their phenotype and they can move from being kind of aggressive, high-testosterone-acting cells where they're chewing things up, breaking down what's dead and cleaning things up, to being kinder, gentler “builder” cells. 

Then those lay down often a beautiful suite, a carpet of tissue, that the skin can then grow over, over a period of time. This happens for a large wound, and for smaller wounds the same thing happens, but it happens in a tighter kind of situation or even a shorter period of time.

Q: How does aging affect our feet, and are there things that elderly people or caregivers can do to support good foot health?

A: As your feet get older, there are several things that happen. 

Some do get a degree of neuropathy, your sensation reduces a bit even as you age. You will find your balance and stability can change a bit, so your angle and your base of gait will affect your interaction with the ground, and increase your chance of falling. In addition to this your skin can atrophy a little bit, becoming thinner. The combination of all of these things makes you less resilient to injury.

Obviously we can't confer immortality on our patients or on ourselves, the more you move - and the more you keep moving in any way you can - the better and more resilient you're going to be. 

There are many devices now that can also help track our health, they are getting more and more common and less and less expensive. These devices now are really helping us “dose” an activity for a patient, like we used to dose a drug. 

Q: How did you first learn about medical grade Mānuka honey? And what was your impression?

A: It’s been more than a quarter of a century since we first started learning about Mānuka honey from New Zealand and the specific characteristics of it. Today, there's a long case-history of its use in nursing, medicine and surgery, and growing data to support the benefits from using it in wounds.

Q: Have you used medical grade Mānuka honey yourself? And what has your experience been with it?

A: We are long time advocates and have used Mānuka honey on many wounds over many years.  What it does is, it donates moisture and absorbs moisture. It also has some aspects of reducing inflammation and some antimicrobial effects. There are several different documented studies that show something you consider to be as simple as honey, can be really, really useful.

Honey has been used in one way or another since forever. In fact, there's a papyrus - the Ebers Papyrus - which is one of the earliest descriptions of any medical therapy. This describes the use of liniment containing honey.

What's old is new! Just because something has been around for a long time doesn't mean you have to adopt something new, although you can continue to update it and improve the science.

Q: We have a lot of questions from people dealing with severely cracked feet. What are some of the common causes of this? What would you recommend to help with this?

A: Severely cracked heels are very common.  It can be painful and often you will find those cracks can become deep crevices, as the skin just becomes more and more dry. 

We will have people put an emollient on the skin, and you can maximize the potential of that emollient by covering it, either with socks at nighttime or a wrap. Doing this with cracked heels will accentuate the efficacy of whatever topical you're putting on.

Q: What is the difference between a fissure and minor cracked heels?  What are the causes of them, and any recommended treatment advice?  

A: Minor vertical cracks that appear on the calluses of heels can be treated with routine exfoliation and pedicure practices, soaking the foot and using a pumice stone to gently remove excess or hardened skin. 

Deeper cracks or ‘heel fissures’ are the result of extremely dry skin, or xerosis, a common condition among people with chronic illnesses such as diabetes, and disorders such as psoriasis, eczema and athlete’s foot. 

Walking barefoot on moisture-pulling surfaces, such as carpeting and sand, can also lead to fissures, as can excess weight and the resulting downward pressure on the feet. Additionally, the subdermal opening at the base of a fissure may allow bacteria to enter and cause an infection beneath the skin, a dangerous occurrence that may lead to ulcers.

See your specialist if your fissures are accompanied by pinkness (a sign of potential infection), redness or any indication of bleeding. 

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Try First Honey® foot care products today: our Foot Rescue Cream is recommended for daily, deep moisturizing and Mānuka Honey Ointment for deeper cracks or minor wounds.  Cover any cracks or wounds with our Mānuka Honey Bandages.

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