Evaluation and Management of Foot Skin and Toenails

  • Lientra Q. Lu, BS; Michael B. Strauss, MD; and Anna M. Tan, DPM
  • Volume 07 - Issue 4

Not only is the skin and its appendages, including nails and hair, the largest organ system in the body, it is the one that has the most contact with the external environment. Consequently, this organ system is the first line of defense in protecting the body from agents in the external environment that could possibly damage the internal contents of the body (Figure 1).1 In addition, this organ system is a window to disease states within its contents, as will be discussed in the next section. Many predispositions cause problems that make the skin and toenails vulnerable to injury and disease. These predispositions include neuropathies, deformities, ischemia, infections, metabolic problems, and congenital disorders. After patients and their caregivers are instructed in skin and toenail care in the lower extremities, inspection of these areas provide objective evidence as to patient compliance. This information can be used as criteria for determining the compliance assessment of the Goal Score (Table 1) and help gauge the frequency of return visits to the health- care provider caring for the patient’s foot conditions.

FIGURE 1. Skin and toenail management are the first line of defense against developing new or recurrent foot wounds.


Legend: Foot wounds and other wounds usually start when the skin and its appendages are no longer able to maintain their protective functions. Skin care and toenail care are the body's first line of defense for maintaining these protective functions.

TABLE 1. Goal Score

TABLE-1Note: The "Goal Score" is another useful tool to determine how successful and how intent the patient and the family are in avoiding a major amputation. Goal Scores greater than 4½ points supports the decision to avoid lower limb amputation and do everything possible for salvage of the nonunion.

Anatomy, Histology and Physiology of the Skin and Toenail

The skin is a part of the integumentary system, an organ system also consisting of hair, nails, and exocrine glands. The skin is only a few millimeters thick but is the largest organ in the body. The average person’s skin comprises 10%– 12% of the body mass and has a surface area of about 2 square meters, or 20 square feet. Skin forms the body’s outer covering and forms a barrier to protect the body from chemicals, disease, UV light, and physical damage.

Epidermal layer The epidermis is the superficial layer of the skin and protects the deeper and thicker dermis layer (Figure 2). The epidermis is made of 40 to 50 rows of stacked squamous epithelial cells (Table 2). The cells are held together along their lateral surfaces by extracellular connections that act as barriers and are called tight junctions. Tight junctions enable the epidermis to function as a selective barrier that prevents most substances in the external environment from entering the body through the skin. Conversely, it provides an envelope to contain the body fluid, which comprises 70% of the body weight. The epidermis does not contain any blood or blood vessels — that is, it is avascular — and epidermal cells receive all of their nutrition via diffusion of fluids from the dermis.

FIGURE 2. Assessment of skin hygiene and lubrication using a 2-point (best) to 9-point (worst) grading system


 Dermal layer The dermis is the deep layer of the skin found under the epidermis. The dermis is mostly made of dense irregular connective tissue along with nervous tissue, tissue fluid, and blood vessels. The dermis is much thicker than the epidermis and gives the skin its strength and elasticity. There are two distinct regions within the dermis: the papillary layer and the reticular layer. Both layers provide nutrients and oxygen for the cells of the epidermis. The nerves of the dermal papillae are used to feel touch, pain, and temperature, while the nerves of the reticular layer sense pressure and pain through the cells of the epidermis.

Subcutaneous layer — Deep to the dermis is a layer of loose connective tissues known as the hypodermis or subcutaneous tissue. The hypodermis acts as the flexible connection between the skin and the underlying muscles and bones and a fat storage area (adipose tissue). Adipose also helps to insulate the body by trapping body heat produced by the underlying muscles.

Toenails Nails are accessory organs of the skin made of plates of keratinized epithelial cells, which are vestigial claws (Figure 3). Fingernails and toenails reinforce and protect the end of the digits and are used for scraping and manipulating small objects. There are three main parts of a nail: the root, body, and free edge. The nail root is the portion of the nail found under the surface of the skin. The nail body is the visible external portion of the nail. The free edge is the distal end portion of the nail that has grown beyond the end of the finger or toe.

TABLE 2. Specialized cells of the epidermis
Type Percentage Function Comments
Keratinocyte 90 Produces and stores the protein keratin, which makes these cells hard, crusty and water-resistant. Originates from stem cells at base of the dermis
Melanocyte 8 Produces the pigment melanin to protect the skin from ultraviolet radiation and sunburn. The number of melanocytes people possess defines their skin color and whether they burn or tan under the sun
Langerhans cell >1 Detects and fights pathogens that attempt to enter the body through the skin. An important component in the first line of defense against skin infections
Merkel cell <1 Gives rise to the sensations of touch, movement, vibration, and pressure Mechanoreceptors. They form a disk along the deepest edge of the epidermis

Nails grow from a deep layer of epidermal tissue known as the nail matrix, which surrounds the nail root. The cells of the nail root and nail body are pushed toward the distal end of the finger or toe by new cells being formed in the nail matrix. Under the nail body is a layer of epidermis and dermis known as the nail bed. The nail bed is pink in color because of the presence of capillaries that support the cells of the nail body. The proximal end of the nail near the root forms a whitish crescent shape known as the lunula, where a small amount of nail matrix is visible through the nail body. Around the proximal and lateral edges of the nail is the eponychium, a layer of epithelium that overlaps and covers the edge of the nail body. The eponychium helps to seal the edges of the nail to prevent infection of the underlying tissues.

Skin and toenail wound challenges The skin and toenails present challenges with respect to the development of wounds that are almost paradoxical. On one hand, these areas are particularly prone to wound problems, especially if one or more of the risk factors for wound development and/or limb amputation, namely: 1) deformity, 2) peripheral artery disease, 3) history of previous foot wound, 4) previous amputation, and/or 5) neuropathy, are present. This is because the skin is always in contact with the external environment, even though covering devices may provide partial barriers, and the skin of the foot transmits the most concentrated forces with standing and walking of any region of the body. Conversely, with simple evaluations and managements, as will be presented in subsequent sections of this article, much can be easily and effectively done to recognize and prevent foot skin and toenail problems.

Predispositions for Skin and Toenail Problems

Comorbidities Skin and toenail problems are particularly prone to develop in selected patient groups such as those with diabetes mellitus, peripheral artery disease, collagen vascular diseases, vitamin and mineral deficiencies, fluid retention, dehydration and aging. Usually skin and toenail problems secondary to these conditions are associated with the following predispositions.

Hypoxia — This problem is most frequently a consequence of atherosclerosis in the patient population with foot and toenail problems. At rest, noncritical tissues, such as the skin and its underlying tissues, have very low metabolic demands. When these tissues are in a healthy state, the minimal blood supply the atherosclerotic vessels are able to deliver is adequate to meet their metabolic demands. With minimal trauma and the need to repair the injury, however, the blood supply may be inadequate to meet the increased demands for fighting infections and healing of wounds. The consequences are problem, nonhealing wounds. The atherosclerosis process is especially associated with diabetes, but there are many other causes of ischemia and wound hypoxia (Table 3). Collagen vascular diseases with associated Raynaud’s phenomena profoundly affect perfusion to the most distal portions of the extremities. Wounds in these areas in patients with collagen vascular diseases are notorious for nonhealing and often result in the need for more proximal amputations. Fluid retention (edema) creates a relative barrier to tissue oxygenation by increasing the diffusion distance from the capillary to the cell. Impaired perfusion from cardiac causes is another cause of tissue hypoxia.

TABLE 3. Ischemia-Related Problems Associated with Wound-Healing Challenges
Problem Presentations Management Comments
Atherosclerotic vascular disease Localized occlusion, diffuse involvement or combinations

Angioplasty and/or revascularization for localized occlusions

Methods to improve wound O2 such as hyperbaric oxygen therapy and medications

Diffuse vessel disease frequently associated with "problem" wounds
Thrombosis Abrupt onset of ischemia with a cold, pulseless, pale limb Thrombectomy and/or thrombolytic therapy  
Venous stasis disease

Hyperpigmentation, bronzing of skin

Venous stasis ulcers

Compression, elevation and vein ligation; most resolve with these measurements

Challenges occur when venous stasis ulcers are complicated by arterial ischemia

Hyperbaric oxygen bioengineered dressings negative pressure wound therapy & skin grafting are useful adjuncts for the most difficult ulcers
Vasculitis Painful, nonhealing wounds in association with collagen vascular diseases Rheumatological interventions including steroids, disease-modifying anti-rheumatic drugs and anti-metabolics to supplement wound care Healing difficult due to involvement of the microcirculation
Fluid retention Stasis dermatitis & ulcerations associated with massive peripheral edema

Measures to reduce edema including diuresis, elevation and compression wraps

Hyperbaric oxygen and fasciotomy if associated with a compartment syndrome

Oxygen diffusion decreases as capillary to sell distance increases due to edema
Miscellaneous including heart failure, obesity & malnutrition

Findings associated with the primary problem

All contribute to wound susceptibility and wound healing challenges

Correction of primary problems in conjunction with wound management

When voluntary weight reduction fails, consider bariatric surgery referral as an adjunct for managing morbid obesity

Once these problems are resolved, the management interventions listed above for the other problems usually effectively resolve the wound problem

Oxygen requirements — Problems arise when the oxygen demands for fibroblast function, angiogenesis and leukocyte oxidative killing are insufficient to meet the skin’s and the underlying tissue’s demands for repair and controlling infection. The consequences are nonhealing and persistence of infection. Of course, tissues die in the total absence of perfusion, such as after thrombotic occlusion of a blood vessel. If the occlusion is localized to arteries large enough for revascularization, perfusion can be restored. Unfortunately, in the situations previously described, perfusion problems usually are also present at the microcirculation level, so these techniques may have only limited success.

FIGURE 3. Komodo dragon and its claws

FIGURE-3Legend: The claws of the Komodo dragon, native to Komodo Islands, Indonesia, are the epitome of keratinization of nails.


Deformities— These are one of the three findings we label as the "troublesome triad," invariably found in the problem wound. Deformities in weight-bearing areas or other areas subject to contact stresses transfer increased pressures to the skin. If the stresses are acute and localized, a blister forms, as often occurs with walking activity associated with new or ill-fitting footwear. If the pressures are intermittent or subcritical (that is, below a threshold where primary damage occurs tot he skin), the skin and underlying tissues react in several ways. First, calluses form over deformities. This is a protective response to the stress manifested by thickening and keratinization of the epithelium. Second, the tissues below the skin over the deformity generate a bursa. With chronic, repetitive stresses, a third response occurs, namely hypertrophy of the bone at the apex of the deformity. This appears on x-rays as periostitis and spurring (eburnations, exostoses, and osteophytes).

Secondary problems from deformities— With continuation of the pressure stresses, secondary problems arise from the reactive processes. If moisture accumulates under the callus, the skin macerates. If the process is not interrupted by debriding the callus and exteriorizing the macerated tissue, erosion  of the skin and introduction of bacteria can occur. If the firm callus cracks or develops a fissure, a pathway is provided for bacteria and moisture to accumulate between the callus and the skin. This provides an environment conducive for bacterial multiplication, development of cellulitis, ulceration, and a pathway for deeper infection to occur. The other problem is the generation of a mal perforans ulcer. This problem is an ulceration that arises from inside to outside due to continued pressure stresses the deformity transfers to the overlying skin. A mal perforans ulcer is characterized by a tract from the skin to the soft tissues immediately overlying the bone. If this protective envelope is breached, bacteria have direct access to bone, and osteomyelitis is a possible consequence. The bacteria may multiply, generate an abscess, and then result in the infection dissecting along tissue planes and/or tendon sheaths. The consequences can lead to a progressive necrotizing, limb-threatening soft tissue infection. Interventions need to be initiated immediately to manage deformities where ulceration is a risk due to their presence.

Neuropathy— This problem contributes indirectly to skin and toenail problems. Peripheral neuropathies are especially common in patients with diabetes, but they can be associated with other problems such as spinal cord injury, Parkinsonism, strokes with residual neurological deficits, multiple sclerosis, trauma, and congenital disorders. Peripheral neuropathies have three presentations that are a factor in the genesis of problem wounds.

Neuropathy affecting the autonomic nervous system results in dryness of the skin. Early manifestations are scaling and loss of the normal elasticity of the skin. The debris from scaling may accumulate to form crusts and plaques. Dry skin is less able to tolerate shear and contact pressure stresses than normally moisturized skin, thereby making it subject to breakdown with normal activities. Evaluation and management of skin problems associated with autonomic nerve dysfunction are discussed in the next section.

Impairment of motor function — Motor neuropathies cause imbalances in muscle activities. Initially these cause nonfixed positional deformities of joints. With persistence, the positional deformities become fixed, resulting in contractures (i.e., permanently stiff and/or malaligned joints). Common deformities observed in the feet because of muscle imbalances include clawed toes, hammer toes, mallet toes, hallux valgus/bunions, and equinus contractures. With solitary muscle weakness or dysfunction, other manifestations such as midfoot hyperpronation from posterior tibial muscle-tendon dysfunction and drop foot from peroneal nerve palsy are observed. Peroneal muscle weakness is manifested by foot inversion, resulting in overloading of the lateral bony prominences of the foot such as the fifth metatarsal base and the lateral aspect of the fifth metatarsal head. Contractures with clawing of the toes pulls the fat pads under the metatarsal heads toward the heel so they no longer offer protection for the metatarsal heads. Dorsal subluxation of the proximal phalanges of the toes at the metatarsal phalangeal joints (with proximal retraction of the toes in association with the claw toe deformities) forces the metatarsal heads plantarward. Attention to these problems with protective footwear, orthotics and surgeries will be discussed in a subsequent article.

The terms dynamic and static should also be considered when describing abnormal posturing of joints. Dynamic deformities indicate that the contractures are due to muscle activity imbalances such as observed early in the course of disease in patients with cerebral palsy, strokes with residual neurological deficits, multiple sclerosis, etc. The contractures are not fixed. With physical therapy, splinting, medications and tendon surgeries, the deformed joints can be corrected and maintained in nearly normal position.
Static deformities imply that the contractures are fixed, that is not correctible with the measures to manage dynamic contractures. Because of the persistence of the deformities, joint capsules become contracted, muscle-tendon units shortened and joints arthrodesed. To correct fixed/static joint contractures, surgery is invariably required.
If wounds, calluses, or toenail problems are already present, a simplified clinical grading system analogous to the other 0- to 2-point assessments is recommended. A grade of 2 points indicates normal sensation and anesthesia is needed for debridements and all other in-office procedures other than toenail trimming and callus paring. A grade of 1 point indicates patients perceive pain with procedures on wounds and toenails, but the procedures usually can be done with no or only locally applied analgesics. A grade of 0 points indicates a total loss of sensation and in-office procedures can be done on the foot without anesthesia. If findings are mixed or intermediate between two grades, half points may be used to reflect the transition.


TABLE 4. Conditions the May Be Predispositions to Skin and Toenail Problems

Condition Problems Comments
Age Slower metabolism, increased doubling times for fibroblasts, impaired circulation, blunted immunological responses, atrophic changes of the skin, etc. Age blunts healing responses and ability for the body to mitigate physical stresses
Androgen deficiency Observed in catabolic states associated with trauma and nutrition problems Consider androgen supplements when these conditions exist
Anemia Compromises oxygen delivery to healing and infection fighting tissues Anemias are associated with other wound healing problems such as chronic infection kidney diseases and malnutrition
Ehlers-Danlos syndrome

Connective tissue disorder with man presentations

Nonhealing wounds and difficult to control infections observed following "clean" surgeries

Problems probably related to defective fibroblast function

Gout (Hyperuricemia)

Uric acid precipitates form crystals () in tissues vulnerable to trauma, especially over bony prominences Uric acid level should be checked especially in patients with wounds over bony prominences
Hypercoagulable states Hypercoagulable conditions include protein C deficiency, anticardiolipin antibodies. Factor V Leiden deficiency, protein S deficiency plasminogen activator inhibitors, homocystein disease, high lipoprotein a, warfarin induced skin necrosis, etc. Work-ups for these conditions are required when seemingly unexplainable skin sloughs (usually massive & multiple) occur

Slowing of metabolism

Dry, pale, cold scaling skin and brittle nails observed

Thyroid function should be assessed in patients on thyroid medications who have wounds
Liver disease

Deficiencies in the formation of proteins, growth factors, cytokines and immunological factors

Hepatitis a comorbidity in some problem wounds

Blood liver panels and hepatitis studies indicated in patients with chronic wounds
Malnutrition Inability to form protein and immunological factors needed for wound healing and infection control It is essential, regardless of the patient's weight, to a certain nutritional status when "problem" wounds exist
Medications Medications such as steroids, nonsteroidal anti-inflammatory drugs, immunosuppressors and disease modifying anti-rheumatological drugs interfere with the inflammatory response These medications coupled with wound healing problems from the underlying diseases (such as collagen vascular diseases)complicate wound healing
Purpura fulminans Intravascular coagulopathy usually secondary to life threatening infection cause widespread thromboses in the microcirculation often result in massive sloughs and even limb losses No effective treatment known to manage the stasis in the microcirculation. Hyperbaric oxygen aids in the demarcation of viable and non-viable tissues and in wound healing
Renal insufficiency and end-stage renal disease Metabolic waste products create an environment adverse to wound healing. Usually other problems such as diabetes, anemias and vascular disease co-exist, which compound wound healing problems Wound healing is challenging, but possible in many situations with strategic management and special wound healing considerations

Acute problems such as nutrition, blood supply and infection interfere with healing.

Chronic problems such as scar formation, deformities and altered blood supply are precursors to the development of new "problem" wounds

Once wound healing has occurred, proactive measures to prevent new problems including orthotics, special footwear and proactive surgeries may be required

Loss of sensation — Sensory neuropathy is a third neurological problem that can indirectly contribute to foot and toenail problems. With loss of protective sensation, impending injury to the skin and toenails may not be appreciated and treatment delayed until more complicated problems develop from the injury. Generally, sensory perception below the “protective sensation” level puts the patient at risk of occult injuries occurring to the skin and toenails without appreciation of pain. Protective sensation is ascertained by testing with a monofilament that bends when approximately five grams of pressure is applied to it. The monofilament is placed on the skin and pressure is applied. If the patient perceives the monofilament touching the skin before it bends, then protective sensation is present. To be valid, the testing should be repeated at the same and different sites. If calluses or other signs of impending wounds or obvious wounds are observed during the exam and the patient walked into the office with no apparent discomfort from the sites, the clinical inference can be made that protective sensation is lacking, regardless of monofilament testing.4

Problems associated with metabolism and immunity — These problems, in particular, are associated with diabetes. A number of other metabolic, immune- system and related conditions, however, may be predispositions to skin and toenail wound problems (Table 4). Elevated blood and tissue fluid sugars provide a more favorable environment for bacterial multiplication and wound infection than in patients with normal blood glucose levels. Atrophy of protective fat pads under metatarsal heads is another finding associated with diabetes. Whether this is a consequence of diabetes, ischemia, common neuropathy, or a combination of these is unclear. The result is less protection of the skin over the metatarsal heads and increased susceptibility to ulcer formation.

Hyperglycemia in patients with diabetes cause increased oxidative stress; increased expression of redox- regulated, proinflammatory genes and transcription factors; and changes to the composition of the extracellular matrix and functional deficits of proteins.5  Some of the changes affect function of mitochondria, suppress cellular immune defense, and alter elasticity of blood vessel walls.6,7 Consequences include microangiopathy, polyneuropathy, and changes in connective tissue composition.2 In patients with diabetes, tissues may become less resilient to sheer and compression stresses. 8 This may be due to glycosylation of proteins in soft tissues, which adds to their rigidity. Loss of elasticity in tendons, ligaments, and joint capsules may contribute to joint contractures and deformities as well as tendonitis and tendon ruptures.

Problems associated with connective tissue diseases — Lupus, dermatomyositis, scleroderma, seropositive arthropathies, and mixed connective tissue disorders, although not usually classified as metabolic disorders, have metabolism-related problems and are notorious for being associated with “problem” and “end-stage” wounds. Vasculitis, a common feature in these disorders, occurs at the microcirculation level and can interfere with perfusion enough to arrest healing of even the most minor wounds. Protein complexes and antibodies cause atrophy and fibrotic changes in the skin and subcutaneous tissues as well as other parts of the body, such as the esophagus and the lungs. Calcium deposition in the subcutaneous tissues (calciphylaxis) serves as a nidus for skin ulceration and infection. The etiology for this is not established but may be due to tissue hypoxia, altered acid-base states, abnormal protein complexes or combinations of these. Raynaud’s phenomenon with intermittent, severe ischemia of the fingers and toes often precipitated by cold exposure or localized trauma may be mediated by the sympathetic nervous system. Consequences of Raynaud’s include soft tissue atrophy, acrosclerosis (ends of the digits become pointed), and nonhealing ulcerations of the fingertips probably after occult trauma. Finally, the use of immunosuppressors (steroids, antimetabolites, nonsteroidal antiinflammatory agents and disease- modifying antirheumatoid drugs) interferes with wound healing and the ability to control infection.

Clinical correlations: A 46-year-old female with a diagnosis of mixed connective tissue disorder on steroids developed a paronychia secondary to an ingrown great toenail. This was managed with surgical decompression and antibiotics. The wound failed to heal, and the distal portion of the toe became necrotic. A partial toe amputation was done. Primary healing appeared to be occurring, but when the sutures were removed, the wound dehisced and developed a necrotic, infected base.
An amputation of the toe at the metatarsal phalangeal joint level was done. Hyperbaric oxygen was given as an adjunct to healing of threatened flaps even though foot pulses were palpable and transcutaneous oxygen measures were normal. This surgical site also failed to heal, and the wound site deteriorated so badly after a couple of months that a more proximal partial first ray amputation became necessary.
When the partial first ray amputation failed, a metatarsal amputation was performed, but gradually dehisced and the wound failed to heal. Subsequently, this led to a below-knee amputation, which healed. Unfortunately a wound developed on the opposed foot, which also eventually ended up in a below-knee amputation on that side.
Comment: This scenario demonstrates the wound-healing difficulties that some patients with collagen vascular diseases may encounter. The distal vasculitis problems in the microcirculation appeared to be so severe that perfusion may only be adequate enough to maintain the steady state but unable to increase enough for wound healing to occur. Palpable pulses and normal transcutaneous oxygen measurements are no guarantee that wound healing will occur in this patient group.

Foot Skin Evaluation and Management

Grading skin condition — Skin assessment is essential for preventing wounds. For those at-risk groups, as previously discussed, checking the skin for precursors of wounds should be done daily by the patient or the caregiver. A simplified, objective grading method based on a 0- to 2-point assessment system (similar to the assessment approach used in generating the Goal Score) is useful for evaluating, documenting, and lubrication (Figure 2). From this grading system, immediate decisions become obvious for appropriate management of the skin. For example, if the skin has a healthy appearance and is moist and pliable (skin assessment = 2 points), the patient and/or their caregivers should be complimented and encouraged to continue the same care they have been doing. If the skin is dry, scaly, and in need of lubrication (skin assessment = 1 point), the patient (or caregivers) should be instructed in foot and leg skin care measures (Table 5). These include the following four steps (Figure 4):

1. Moisturizing and cleansing:

This is done by showering, bathing, soaking the feet in a basin or wrapping the feet and legs with a warm, moist towel. Warm, not hot, water should be used. The skin should be gently cleansed of debris using a soft cloth and a mild soap or skin cleanser during the moisturizing period. Contact with water should be for periods less than 10 minutes to prevent maceration of the skin.

2. Drying the skin:

This is done with a soft towel or cloth. Additional debris on the skin may be removed while drying the skin. The skin between the toes should be carefully dried and cleansed of debris to prevent fungus infections from moisture remaining in the intertriginous region. If fungus infection is apparent with findings of redness, fissures, dead skin, localized scaling of the skin and/or odor, an over-the-counter fungicidal agent [e.g., tolnaftate (Tinactin®), clotrimazole (Lotrimin®), miconazole (Micatin®), etc.] should be used for application to the affected areas after skin care is completed.

3. Lubrication and massage:

After the skin is dry, it should be lubricated and massaged with a lubricating agent. The active lubricating agent in most skin lotions is either a petrolatum/glycerin, lanolin or silicon-based product. A multitude of products are available (Figure 5). Usually lubrication and massage only take a couple minutes of time since the moisturized skin tends to readily absorb the lubricating agent. Petrolatum jelly (Vaseline®) is the “ideal” lubricating agent because of its effectiveness and economies. The disadvantages are it requires effort to work it into the skin, and it can leave a greasy residue.


4. Removal of residuals of the lubricating agent:

This should be done with a soft cloth or towel. Once this step is completed, the skin should feel soft and pliable without a greasiness feeling or visible residuals of the lubricating agent on the skin. Care should be given to removing residuals of the lubricating agents from skin creases and between the toes where moisture accumulation under the agent could lead to maceration and fungus infection.

figure4-fourstepskincleaningandlubZero-point skin grade — If plaques, scales, or hyperkeratinization are present on the skin, skin care should be done in the office or patient’s hospital room (Figure 6). Plaques, scales, and hyperkeratinized skin may be debrided with a scalpel. If the skin is in need of cleansing and debridement, a finding frequently noted after cast removal, pulsatile lavage is an effective technique for removing loosely adhering skin debris. While plaque and callus removal is usually done by the physician, the four-stage foot and leg skin-care measures are usually done by assistants helping the physician. While performing the initial skin care for the patient, the assistants teach the patients how to do the four-step skin-care protocol. How well they follow these instructions becomes apparent at the next return visit, reflects patient compliance, and is a criterion for how often the patient needs to return for follow-up care.

For efficiency sake in the office setting, the abbreviations FSC (foot skin care) and TLC (tender loving care) are useful. For example, when it is ascertained that FSC (including the legs, if necessary) needs to be done in the office, the patients are informed that we plan to do TLC for their skin and in the process teach them how to do FSC in the home setting.
Usually when patients hear the words “tender loving care,” they feel they are getting special attention. The use of these abbreviations also saves time for documentation of the treatment plan.
Another situation where TLC is effectively used is for cleansing and lubrication of the skin after cast removal. When this is done, the patients feel they are getting an additional “extra measure of care.”

FIGURE 4. Four-step skin cleaning and lubrication technique


FIGURE 5. Skin and cleaning lotion choices

FIGURE-5Legend: Innumerable skin cleaning and moisturizing agents are available. Choices differ by addition of colors, perfumes, anti-aging agents, sun protection factors, smoothing and firming products, etc.


FIGURE 6. Debridement of skin in the office


Toenail Evaluation and Management

Toenail evaluation — Toenail care deserves equal consideration to foot and leg skin care as a prevention strategy for wounds. Any patient who has risk factors for wounds (deformity, peripheral vascular disease, history of previous wound, previous amputation and neuropathy) should have his/her toenails inspected each time the feet are examined. Although many conditions cause toenail abnormalities, four findings are most frequently associated with “problem” wounds (Figure 7). Usually two or more findings are present and include the following:

1. Dysmorphic changes: This finding indicates that the shape of the toenail is abnormal. The toenail end may be curved like the shape of a spoon, vaulted like a cathedral ceiling or curled like a ram’s horn. Usually dysmorphic changes are due to abnormalities in the nail bed from underlying bony deformities or from pressure effects from footwear. When the toenail edges are curved, debris often becomes embedded between the curved toenail edge and the underlying skin.

2. Dystrophic changes: These problems are reflected in abnormal growth of the toenail and usually arise from problems in the nail matrix from circulation, disease, trauma, toxic substances or congenital problems. Presentations include thickened, furrowed, discolored, and hypoplastic toenails.

3. Fungus infected: Although fungus infection may be a primary problem of toenails, in patients with sensory neuropathy, occult trauma may also be a cause. With occult trauma be partially avulsed from the nail bed without being recognized. This may allow moisture to accumulate under the toenail and provide an ideal environment for the fungus to grow. Fungus infected toenails become discolored, thickened, friable, honeycombed and/or laminated (layers of infected toenail and debris).

4. Ingrown: Direct trauma or contact pressure from shoe and sock wear may force the edge of the toenail into the recess between it and the paronichium. This may introduce bacteria and cause a localized cellulitis or abscess (paronychia) or pyogenic granuloma. Another way bacteria are introduced into the skin is when the distal edge breaks off or is trimmed off leaving a hook shape to the edge of the toenail. As the toenail grows outward, the hook end of the toenail grows into the adjacent paronichium.

Grading toenail condition — As in the skin grading system, a simple, quick-to-use 0- to 2-point assessment is recommended for evaluation and management of toenail problems (Figure 7). Management of toenails in patients with risk factors for wounds becomes obvious when the assessment system is used. If the toenails are the proper length and normal in appearance (nail assessment = 2 points),  the patients should be complimented and encouraged to continue the same care they have been giving to their toenails. If the toenails are long and/or the ends of the toenails are jagged (nail assessment = 1 point), but otherwise normal in appearance, two options exist. If the patient is agile and his/her vision is OK or the caregivers are conscientious, they may trim the nails straight across. More preferable, especially if sensory neuropathy is present, is to have them use a disposable nail file to keep the nails at the proper lengths with frequent filings. If the patient and/or caregivers are unable to care for the toenails, then they should be trimmed with nail cutters in the office setting by care providers properly trained in toenail care.

FIGURE 7. Assessment of toenails using a 2-point (best) to 0-point worst) grading system

FIGURE-7* Risk factors for wound development include: deformity, previous amputation, peripheral artery disease, previous wound and/or neuropathy.

A small rotary craft tool with a cylindrical sanding attachment very effectively debulks and contours thickened toenails.
Personnel who use the tool should be gloved, gowned, caped, and masked to protect themselves from the flying debris that arises from this technique.
A new sanding cylinder needs to be used for each patient. The flying debris generated by the rotatory sander should be simultaneously vacuumed as it is produced.


FIGURE 8. Common toenail problems


figure8Legend: These examples are among the most frequent toenail problems encountered in a wound healing center. They should be always be documented and managed appropriately.

If the toenails are dysmorphic, dystrophic, fungus infected or ingrown (nail assessment = 0 points, Figure 8), toenail management should be done by podiatrists, orthopaedic foot surgeons or health-care providers trained in toenail care using sterilized nail instruments specifically designed for these purposes. Embedded material at the nail margins should be debrided. The hooked ends of ingrown toenails should be trimmed proximally to achieve a smooth nail edge. This may require trimming the nail edges along the eponychium to a curved rather than straight-across toenail end (Figure 9). Thickened, fungus infected toenails should be thinned until they are tissue paper thickness (Figure 10).

Toenails that are no longer attached to the underlying nail bed should be debrided proximally until they are attached to the nail bed. This usually eradicates the infected portion of the toenail. In this situation, a sensory neuropathy can be a boon to toenail care since very complete toenail care can be done without requiring local anesthetics or the patient experiencing pain. Once this toenail care is completed, the edges of the toenail and the recesses should be painted with an iodine containing disinfectant for infection prophylaxis.

Zero-point toenail grade — The above approach to complicated toenail problems (nail assessment = 0 points) exemplifies the surgical perspective, that is to aggressively eliminate the problem using appropriate instruments. The time required to achieve this goal is measured in minutes. The other approach when fungus infection of the toenail is present is the medical one using oral fungicidal agents. The more severe the involvement, the less likely fungicidal agents will be effective. At best they cure the infection in 40-70% of the cases.10


In the United States it is estimated that 35 million people are affected with toenail infections. About $1 billion a year is spent on medications trying to eradicate them.9,10


In the USA, over a billion dollars is spent each year on oral and topical agents that are used to treat toenail infections.10 Furthermore, medical management of infected toenails may take takes months or more to cure the problem, if indeed it cures it at all, and monitoring of toxicity from the agent with liver function tests is often required. Once initial debridement of the complicated toenail problem is done, the patient is usually asked to return in a couple of weeks to “fine-tune” the toenail appearance by hand filing and further contouring the toenails.

Laser treatment of fungus- infected toenails is currently being investigated (not yet approved by the Food and Drug Administration). The treatment with lasers costs $1,000 or more and has reportedly been observed to be effective in 50% to 75% of cases.11


“Do’s” and “Don’ts” Pertaining to Skin and Toenail Care

In the previous article, we presented a list of “do’s” and “don’ts” that should be taught to patients with risk factors for foot wounds and/or their caregivers. A number of them are pertinent to skin and toenail care. For this reason, those that apply to foot skin and toenail care are now repeated in tabulated form in this section.

FIGURE 9. Toenail care techniques

FIGURE9Legend: Instrument selection for toenail management depends on the severity (assessment grade-Figure 7). Often two instruments are used to optimize outcomes such as a nail clipper for trimming and a disposable nail file for achieving smooth ends and contouring the toenails.


FIGURE 10. Establishment of healthy margins for severely diseased toenails

figure10Legend: Appropriate toenail care to eradicate fungus disease and ingrown margins may require trimming the nail to the matrix and removing embedded debris and ingrown portions from the eponychium. If bleeding occurs, a silver nitrate applicator effectively cauterizes the bleeding site. Because of the extent of the debridement, the toenail and adjacent eponychium should be "painted" with an iodine solution or similiar disinfectant.


“Do’s” with Respect to Preventing Skin and Toenail Problems

  • Inspect feet daily (look for area of erythema, attenuation of skin, discharge, or odor).
  • Practice good foot hygiene, including skin lubrication (use the 0- to 2-point assessment system to evaluate and determine the appropriate management).
  • appropriate toenail care (this may be done by the patient and/or the caregiver with assessment of 2 or 1 point. If the patient’s mobility, vision, or both are a concern, however, and/or with assessment of 0 point, the toenail care should be done by properly trained providers).

“Do’s” with Respect to Preventing Skin and Toenail Problems

  • Don't walk barefooted (in the presence of neuropathy, patient might not appreciate a punctured wound, which can inoculate the underlying tissue and lead to serious infections).
  • Don't use heat on the feet and don’t soak the feet in hot water (with impaired sensation, the patient might not appreciate that the water will burn the skin and with poor circulation, the patient has impaired ability to dissipate the heat stress to the skin, thereby resulting in burns).
  • Don't use chemicals or sharp objects to trim calluses (same consideration as for not walking barefooted).
  • Don't trim corners of toenails (unsterile, over-the-counter toenail clippers may accidentally cut into the eponychium and lead to infections).
  • Don't use toenail polish, especially if risk factors for foot wounds exist (toenail polish may trap moisture and provide an environment for the fungus to thrive).


The skin of the feet and the toenails are windows to the interior of the body. Being that they are the furthest distance from the body core, they may be the first to demonstrate circulation problems and the development of neuropathy. Consequently, what you see in these structures can tell you a lot about the patient’s wellness. Most patients, their caregivers, and even health-care providers often do not take the time to look into the window, that is, to examine the skin of the legs and feet and inspect the toenails. The other benefit of examination of these structures is to confirm how well these patients follow instructions and are compliant with recommendations. When risk factors for wound development in the feet and legs are present, the skin and toenails are without question the first line of defense for their prevention. Fortunately, as this article shows, evaluation and management of skin and toenail problems can be objective as well as quick and easy to accomplish.


  1. Staruss MB, Miller SS. Addressing foot skin and toenail concerns in diabetics. J. Musculoskeletal Medicine. 2007; 24(7):312-319.
  2. Strauss MB, Moon H, La S, Craig A, Ponce J, Miller SS. The incidence of confounding factors in patients with diabetes mellitus hospitalized for diabetic foot ulcers. Wounds. 28(8):287-294, 2016.
  3. Strauss MB, Manji KA, Miller SS, Manji AA. Bursa and callus: friend or foe. Wound Care & Hyperbaric Medicine. 2013; 4(2):19-28.
  4. Wolhrab J, Wolhrab D, Meiss F. Skin diseases in diabetes mellitus. J Dtsch Dermatol Ges. 2007; 5:37-53.
  5. Wautier JL, Guillausseau PJ. Advanced glycation end products, their receptors and diabetic angiopathy. Diabetes Metab. 2001; 27:535–542.
  6. Obrosova IG. Increased sorbitol pathway activity generates oxidative stress in tissue sites for diabetic complications. Antioxid Redox Signal. 2005; 7:1543-1552.
  7. Buckingham BA, Uitto J, Sandborg C, et al. Scleroderma-like changes in insulin-dependent diabetes mellitus: clinical and biochemical studies. Diabetes Care. 1984 Mar-Apr; 7(2):163-9.
  8. Elewski BE, Charif MA. Prevalence of onychomycosis in patients attending a dermatology clinic in northeastern Ohio for other conditions. Arch Dermatol. 1997 Sep; 133(9):1172-3.
  9. Roberts DT, Taylor WD, Boyle J. Guidelines for treatment of onychomycosis. British Association of Dermatologists. Br J Dermatol. 2003 Mar; 148(3):402-10.
  10. Gupta AK, Ryder JE, Johnson AM. Cumulative meta- analysis of systemic antifungal agents for the treatment of onychomycosis. Br J Dermatol. 2004 Mar; 150(3):537-44.
  11. Singer N. False start on a laser remedy for fungus. The New York Times. 2009 March 20; p 20.

About the Author


MICHAEL STRAUSS, M.D., an orthopaedic surgeon, is the retired Medicine Program at Long Beach Memorial Medical Center in Long Beach, California. He continues to be clinically active in the program and focuses his orthopaedic surgical practice on evaluation, management and prevention of challenging wounds. Dr. Strauss is a clinical professor of orthopaedic surgery at the University of California, Irvine, and the orthopaedic consultant for the Prevention- Amputation Veterans Everywhere (PAVE) Problem Wound Clinic at the VA Medical Center in Long Beach. He is well known to readers of WCHM from his multiple articles related to wounds and diving medicine published in previous editions of the journal. In addition, he has authored two highly acclaimed texts, Diving Science and MasterMinding Wounds. Dr. Strauss is actively studying the reliability and validity of the innovative, user-friendly Long Beach Wound Score, for which he already has authored a number of publications.



ANNA M. TAN, DPM, is the chief resident of podiatric medicine and Center. She graduated cum laude from the University of Southern California in 2006 and received the Dean’s Award for her undergraduate research on netrin-1, a protein involved in axonal guidance. Subsequently, she attended the California School of Podiatric Medicine at Samuel Merritt University in Oakland, California, receiving her doctor of podiatric medicine degree in 2014. Dr. Tan has special interests in surgical management of problem wounds and limb salvage. In her spare time, she enjoys Bikram yoga, cooking and traveling.



LIENTRA LU is a research coordinator at the VA Medical Center in Long Beach, California, under the guidance of Dr. Ian Michael Strauss. She is also an administrative assistant in the accounting department of the Southern California Institute for Research andEducation (SCIRE). She received a bachelor of science degree in chemical biology at the University of California, Berkeley, in 2015 and subsequently has taken medically related courses at the University of California, Los Angeles. Miss Lu is helping with diabetic foot and venous leg ulcer studies at the VA Medical Center while also serving as an assistant in patient care at the PAVE Clinic there. She also works with the American Red Cross in her other interest, disaster preparedness.


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