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Canadian Medical Alliance for the Preservation of the Lower Extremity

Diabetic Dermatology (The Skin of the Diabetic Patient)

 

Many diabetic patients develop abnormal changes in the skin.  In fact,
one study found skin changes developed in 84% of diabetic patients.

Furqan S, Kamani L, Jabbar A.  Skin manifestations in diabetes mellitus. 
J Ayub Med Coll Abbottabad. 2014 Jan-Mar;26(1):46-8.

So we've devoted a page to this discussion.

Most of the skin changes associated with diabetes are associated with abnormal
changes in circulation or neuropathy (the loss of normal nerve function). 

In many cases of diabetes, there is both neuropathy and poor blood flow.

 

We discuss more about neuropathy here, but as a quick summary, diabetic neuropathy is a condition that creates abnormal function in a variety of nerves, like sensory nerves (nerves that feel sensations like pressure, pain and light touch to help us sense the outside world) and motor nerves (which attach to your hands, feet and toes to move you.)  Abnormal motor nerve function puts the patient at risk of deformity.  Abnormal sensory nerve function puts the patient at risk for ulceration, or holes in the skin.

 

But neuropathy can also affect the autonomic nerves--the nerves that perform functions we don't think about.  For example your blood pressure is controlled by autonomic nerves, as is the rhythm and pace of the heart, and the digestion of food in our guts. 

Perspiration and moisture content of the skin are also controlled by nerves.  So with autonomic neuropathy we may see Texture changes.

Occasionally, as seen to the left, diabetic patients develop an increased in moisture content (maceration) through an increase in perspiration (hyperhidrosis).  This is amplified when the foot is kept in heavy socks and shoes for periods of time. 

 

High moisture content can weaken the skin and lead to ulceration and infection.

 

Much more commonly, as seen in the images to each

side and below, diabetes leads to excessively dry skin

This is also known as xerosis or xeroderma.  (The 'x'
in these words
is pronounced as a 'z', so it's

pronounced zerO-sis and zero-DER-ma).  You see
examples to each side and below.

 

Dry, cracked skin may lead to fissures and bleeding. 
The skin becomes weaker and
less resilient to
pressure and shear,
which may lead to ulcerations.  

These compromises to the skin may lead to infections.
Sometimes infections get out of hand, particularly so
in diabetics.  And this can make the patient more
susceptible to amputation.

Examining the foot daily to monitor for any breaks
in the skin and maintaining proper moisture balance
by wicking away fluid, regular changes in socks and
shoes in the damp foot, and applying moisture to the
foot with excessively dry skin is vital.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The skin on the legs can also become thin and shiny and waxy in appearance. 

There can also be loss of hair in the legs and feet, both from diminished circulation that often accompanies diabetes, and the diabetes itself.

Changes in the skin of this nature affect approximately half of diabetics, becoming more common with time.

Source:

James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin:
Clinical Dermatology.  Saunders Elsevier. ISBN 0-7216-2921-0.

Fungal Infections of Skin and Nails

Thin, cracked, weakened, compromised skin can also make a diabetic susceptible to fungal infections of the skin.  This is known as tinea pedis, or more colloquially as athlete's foot (left).  The fungus is often white, but may be red, inflamed, and 

itchy (below left) as well.

With time, fungus may spread from the skin to the nails, making the nails, thick, discolored and misshapen. And the nails can harbour the fungus, making reinfection of the skin a frequent, recurrent event.

 

The nails can become quite thick, misshapen and difficult to maintain (below right), particularly when many diabetics are older and have difficulty bending. 

And many diabetics, and older people generally, have difficulty seeing their feet, making difficult even routine footcare tasks--like washing the feet, cutting the nails, and keeping the feet properly moisturized.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bruising and Infections

Thin, dry, neuropathic skin can also make a diabetic's skin more fragile and
susceptible to injury.  This is often seen as bruising, which may occur with little
in the way of trauma. 

But if the skin is compromised enough to breach the barrier, bacterial infections
may develop.  This is quite common in neuropathic patients who cannot feel the
damage being done to the feet.  Before the patient to the right removed his foot
from his sock, he had no idea there had been any injury to the foot.  

The patient pictured below left could not recall any injury to his leg. 

 

Below center, the damage to the toe resulted from simply wearing a shoe that
rubbed the top of the toe.  The damage was significant enough that the toe
became dusky.  This led to gangrene and amputation of the digit.  Note the tight,
thickened, inflexible skin known as sclerosis.  This will be discussed below.

The patient below right simply leaned against a rung of a ladder. 

 

Injuries like these exhibit significant injury from what a non-neuropathic patient

would find incidental and non-injurious. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Calluses and Corns

Diabetic motor neuropathy may often result in crooked toes, prominent bones, and
abnormal gait, and this can produce sites of abnormal pressure and friction.  This may
result in areas of thickened dead skin.  Depending upon their location, these areas of
thickened dead skin build up are known as a corn or callus.  (The word "callous" is the
adjective form--as in calloused skin or a callous person.)  

In those patients with sensory neuropathy, the patient may not feel or notice corns
and calluses developing, and they can become quite thickened.  If bad enough, the
callus or corn may create an ulcer (hole in the skin), as discussed below.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ulcers

When sensory loss (sensory neuropathy) is present, the thickened skin of
corns and calluses (above) can begin to tear the living skin below, and an
ulcer may develop (right). 

The patient may not be able to feel the damage that creates the ulcer, and
the damage may become significant.  Ulcers may put the patient at risk of
infection of the soft tissues or bone.  This may result in lengthy and expensive
treatments.  They may sometimes lead to amputation and premature death. 

Ulcers are, of course, the main topic of this website, and there are many
photographs of ulcers throughout this website. 

To learn more about abnormal biomechanics associated with wounds, click
here

To learn how the skin breaks down to form wounds, click here.

 

Diabetic Dermopathy

Diabetic dermopathy (pronounced derm-AH-path-ee) is a disorder of the
skin that results in brown or, less frequently, pinkish discolorations of the
skin.  They're usually round or oval, and tend to develop on the front
(anterior portion) of the legs.  The discolored lesions may be scaly, and
may develop a slight depression.  

While the medical literature gives a wide range of prevalence, it's safe
to say this is one of the most common skin pathologies that develop with
diabetes.  

 

To the right is an early case of diabetic dermopathy.  The image below
demonstrates a significantly more advanced diabetic dermopathy.

The cause of the condition is unknown, but microscopic examination
demonstrates altered microcirculation, a leakage of blood contents into
the skin, and an increase in melanin (the component of skin that provides
pigment).   

Diabetic dermopathy is more common in those who have had diabetes for
several years, and in those with poor sugar control.  They are more likely to
be associated with more severe neuropathy, retinal disease and kidney disease,
so the presence of diabetic dermopathy should raise a clinical suspicion of
these other pathologies. 


However, the lesions, themselves, do not typically hurt, they don't ulcerate,
and the discolorations, themselves, do not need to be treated.
 

Good sources on diabetic dermopathy:

 

Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007).
Dermatology: 2-Volume Set. St. Louis: Mosby. ISBN 1-4160-2999-0.

James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin:
Clinical Dermatology. Saunders Elsevier.  ISBN 0-7216-2921-0.  

Morgan, AJ, Schwartz, RA. "Diabetic dermopathy: a subtle sign with grave implications".
J Am Acad Dermatol. vol. 58. 2008. pp. 447-51.

Kiziltan, ME, Benbir, G, Akalin, MA. "Is diabetic dermopathy a sign for severe neuropathy
in patients with diabetes mellitus? Nerve conduction studies and symptom analysis".
Clin Neurophysiol. vol. 117. 2006. pp. 1862-9.

Abdollahi, A, Daneshpazhooh, M, Amirchaghmaghi, E, Sheikhi, S, Eshrati, B,
Bastanhagh, MH. "Dermopathy and retinopathy in diabetes: is there an association".
Dermatology. vol. 214. 2007. pp. 133-6.

Brugler, A, Thompson, S, Turner, S, Ngo, B, Rendell, M. "Skin blood flow abnormalities in
diabetic dermopathy". J Am Acad Dermatol. vol. 65. 2011. pp. 559-563.  

Shemer, A, Berman, R, Linn, S, Kantor, Y, Friedman-Birnbaum, R. "Diabetic dermopathy and
internal complications in diabetes mellitus".  Int J Dermatol. vol. 37, 1998.  pp.113-115

Romano, G, Moretti, G, DiBenedetto, A, Giofre, C, DiCesare, E, Russo, G.  "Skin lesions in
diabetes mellitus: prevalence and clinical correlations". 
Diabetes es Clin Prac. vol 39, 1998.  pp.101-106

McCash, S, Emanuel, PO. "Defining diabetic dermopathy". J Dermatol. vol. 38. 2011.
pp. 988-92.

Vitiligo

Vitiligo (vih-till-EYE-go) is a skin disorder where patches of the
outermost layer of skin (epidermis) loses its natural pigment
(melanin), and the skin becomes white.  The cause is unknown,
but a leading theory is that the cause may be autoimmune. 
One does not have to be diabetic to develop vitiligo, but it is
somewhat more common in diabetics, particularly Type 1 diabetics. 
Vitiligo typically involves the trunk or face, but may involve the
lower extremity.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Diabetic Blisters (Bullosis Diabeticorum)

 

Occasionally diabetics may develop blistering, typically with no obvious cause.  They may occur in multiples and may occur on either the upper or lower extremity but are more common in the foot.  They are typically painless, and have no surrounding inflammation.  They tend to resolve on their own, but healing can become an issue in patients with poor circulation or if they become infected.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Necrobiosis Lipoidica

Similar to, but much rarer than diabetic dermopathy, Necrobiosis Lipoidica (NL), sometimes known as Necrobiosis Lipoidica Diabeticorum (NLD), also causes spots on the skin, and also most common in the anterior portion (front of) the lower leg. 
They may also involve the trunk, upper extremities, face and head.  Lesions are usually more pinkish (below left) to red (center) to a maroon (below right).  Lesions frequently have a darker red border. 

 

In lighter-coloured lesions, you may be able to see blood vessels in the center of the lesions. 

 

 

The photos above left and above center appear courtesy of www.hasshe.com.  

Necrobiosis lipoidica lesions usually begin as

isolated plaques, but may coalesce into larger

regions.  

Lesions can be inflamed, itchy and uncomfortable. 

If they progress, NL lesions may ulcerate (right). 

 

Ulceration occurs in less than one-third of cases.

 

 

 Acral Gangrene

 

 

Diabetics will often develop poor circulation as a result of arterial disease that will often affect both large and small arteries.  This is even more likely if the patient smokes or is on dialysis.  It commonly presents as gangrene--the death of the tissue.  

 

Gangrene may also be known as acral dry gangrene, where 'acral' refers to the periphery of the body (fingers and toes) and 'dry' refers to death of the tissue from blood loss and not as a result of infection.  

 

The toes, being furthest from the heart, having very small blood vessels, and receiving a significant amount of trauma from walking, are often the first to exhibit the effects of circulation, as seen in these images.  

Gangrene of the toes may involve a single toe (left), a combination of toes (below left and center), or it may expand to extend up the foot, (below right).

 


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

While usually associated with the toes, dry, acral gangrene may

also be present in the fingers (below left).  This typically results
in amputation (below right).

   

 

 

 

 

 

 

 

 

 

 

 

 

 

Eruptive Xanthomatosis

Xanthomatosis (Zan-though-muh-toe-sis) refers to a group of lentil-sized bumps on the skin. They're typically yellow (xantho- means 'yellow' in Greek), but may also appear red or surrounded by a red border. 

They consist of fat and cholesterol. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

These two images appear courtesy of http://atlasdermatologico.com.br. 

 

 

Disseminated Granuloma Annulare

Disseminated (meaning 'spread over a wide area') Granuloma (meaning 'inflamed vascular tissue') Annulare ('in a ring shape') refers to a skin condition meaning just that--a series of circular rings in the extremities. 

They typically feature a reddish color, with a border.  

These lesions do not necessarily require treatment.  With time, they often fade on their own.  However a variety of treatments do exist, including steroids, and light therapy.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

      The image above appears courtesy of http://atlasdermatologico.com.br.                 The image above appears courtesy of https://www.epharmapedia.com

 

Sclerosis

 

Sclerosis, a word of Greek origin means an 'abnormal hardening," and
refers to thickened, tight, stiff skin. 


Sclerosis is sometimes known as induration.  

Sclerosis can be seen in a variety of locations, such as the leg to the right. 
But it is most problematic around joints, such as the ankles, knees, and elbows. 

It is seen, too, in the digits of the body--both fingers and toes, as seen below),
where it is known
as digital sclerosis.    The joints become stiff, less dexterous,
less functional. 
In the lower extremity, it is sometimes accompanies the
contractures of the digits caused by motor
neuropathy.  Stiff, sclerotic skin is
more susceptible to injury.

 

 

“A warrior is defined by his scars, not his medals.”
             
               -- Matshona Dhliwayo

Although the world is full of suffering, 

it is also full of overcoming it.  

--Helen Keller

texture, background. Maple Leaves yellow

This page written by Dr. S A Schumacher
Podiatric Surgeon
Surrey, British Columbia  Canada

With the exception of those photos so marked,
all clinical photographs are owned and provided
by Dr. S A Schumacher.  They may be reproduced for educational purposes with attribution and a link to:  


Dr. S A Schumacher, Surrey, BC Canada 
www.CanadianMAPLE.org

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