September 2017 - Volume 30 - Issue 9

  • Richard "Sal" Salcido, MD
  • 1527-7941
  • 1538-8654
  • 12 issues per year
  • 1.088

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Relative Temperature Maximum in Wound Infection and Inflammation as Compared with a Control Subject Using Long-Wave Infrared Thermography

Chanmugam, Arjun; Langemo, Diane; Thomason, Korissa; More

Advances in Skin & Wound Care . 30(9):406-414, September 2017.

Clinical Management Extra


Welcome to Wound Clinical Solutions Investigation (CSI). See if you can make the diagnosis.

Q.  A 52-year-old male patient with a history of diabetes presented to the clinic with friable hypergranulation tissue and bleeding from the side of his big toe. What's the diagnosis?

 CSI photo 6-30-17.jpg

A. This is an ingrown toenail, or onychocryptosis, which usually involves the great toenail. This condition is characterized by the corner or side of the nail plate growing into the periungal skin.  Eventually, puncturing of the soft flesh can result in pain, redness, swelling, bleeding, and infection. 

What causes an ingrown toenail?  There are several factors that are thought to be the cause of onychocrytosis, including:

  • Genetic predisposition: Ingrown toenails tend to run in families.  Some people are born with congenital misalignment of the big toenail rendering the nail discolored, thickened, triangular, and oyster-shell like. 
  • Inappropriate nail care:  Cutting the toenail too short and tapering or rounding the corners of the nail to make it follow the curvature of the toe tend to promote the shrinkage of the distal nail bed. This limits the space for the regrowing wide nail and encourages the nail to grow into the skin.
  • Excess moisture: Individuals with hyperhidrosis and those who sweat when exercising may have excess moisture in the toe area.
  • Inappropriate footwear: Wearing shoes or socks that are too tight puts pressure on the nail and forces it to grow into the skin.
  • Repetitive trauma: Activity that injures the nail, such as kicking a soccer ball or hitting the pedals during driving, may contribute to an ingrown nail.

The severity of ingrown toenails is categorized into 3 stages: Stage 1 is characterized by erythema, slight edema, and pain. Stage 2 involves more severe symptoms and formation of granulation tissue.  In Stage 3 (shown above), abscess formation, chronic induration of the lateral nail fold, and nail fold hypertrophy, are evident along with other coexisting symptoms.

How should an ingrown toenail be treated?

The scientific evidence for the treatment of ingrown toenails remains scarce and somewhat controversial.  All in all, partial nail avulsion followed by either phenolization or direct surgical excision of the nail matrix seems to be the most effective treatment. Phenol is a chemical cauterant that also has antiseptic and local anesthetic activity.  Other nonsurgical options are used widely but their effectiveness is inconclusive:

  • Packing using wisps of cotton or dental floss to place under the ingrown lateral nail and lift the nail off the skin.
  • Taping using tapes to pull the lateral nail fold away from the lateral nail edge.
  • Nail braces are designed to flatten the nail.
  • Foot hygiene: Keep the feet clean and dry.
  • Footwear adjustment to prevent pressure to the nail.
  • Nail care: Trim the nails no shorter than the edge of the toe and gently file any sharp edges with a nail file.

 

 

 

 

 

 

Dressings with pH Sensors

Wound healing involves a complex sequence of biochemical processes leading to a significant variation in the levels of glucose, oxygen, pH, and other metabolic parameters. The pH level rises to 8 before falling to 5 or 6 during wound healing. A sustained high pH level is a signal that wound healing is stalled.  Researchers from Empa's Laboratory for Biomimetic Membranes and Textiles teamed up with ETH Zurich, Centre Suisse d'Electronique et de Microtechnique, and University Hospital Zurich to develop a high-tech system that incorporates a customized fluorescent sensor in the dressing to monitor pH changes in wound fluids. The sensors are composed of benzalkonium chloride and pyranine.  Benzalkonium chloride is a substance also used for conventional medical soap to combat bacteria, fungi, and other microorganisms. Pyranine is a dye that glows at pH levels between 5.5 and 7.5 in the visible or ultraviolet (UV) range.  Weaker and stronger changes in color intensity can signal whether the wound fluid is alkaline or acidic. It might one day even be possible to read the signals with the aid of a smartphone camera. Combined with a simple app, wound care clinicians would have a tool that enables them to easily and conveniently read the wound status "from outside," even without a UV lamp.

Substance P in Tears as a Biomarker of Neuropathy

Substance P is a neuropeptide that acts as a neurotransmitter and is also involved in maintenance and nutrition of the cornea. The cornea has a rich network of fine nerves, which play critical roles in protecting and healing the surface of the eye. Corneal nerve fiber density, measured by confocal microscopy can predict diabetes-related damage to the peripheral nerves; one of the most common diabetes complications that causes symptoms, including pain and numbness of the hands and feet.

Researchers from the University of New South Wales, Sydney, Australia, had discovered that tear samples from patients with diabetes show low levels of substance P.  The researchers measured substance P levels in the natural tear film in the eyes of 9 adults with diabetes and a control group of 17 nondiabetic subjects. Patients with diabetes had substantially lower levels of substance P in tear film samples compared to healthy controls. On confocal microscopy, the diabetic patients also had a significantly lower corneal nerve fiber density, indicating loss of corneal nerve fibers. High levels of substance P may be related to early damage to the corneal nerves contributing to the development of corneal ulcers and poor wound healing in patients with diabetes.  Substance P levels were positively correlated with the corneal nerve fiber density measurement suggesting that the neuropeptide in tears may be a potential biomarker for corneal nerve health. Tear analysis may become a useful, noninvasive test for assessing the risk of peripheral neuropathy in patients with diabetes.

Mitochondria-targeted Antioxidant to Treat Diabetic Wounds

Researchers from the Lomonosov Moscow State University have tested the use of mitochondria-targeted antioxidant to treat diabetic wounds in mice. The experiments on cell cultures, along with detailed histologic examination of these wounds have shown that SkQ1 improved wound epithelization and granulation tissue formation stimulated vascularization in all the major steps of wound healing. It provides further evidence that reactive oxygen species produced in mitochondria play an important role in pathogenesis of diabetic wounds.

Ficin for Wound Healing

Enzymes, such as trypsin, chymotrypsin, or collagenase are used to necrotic tissues and fibrin clots and they have been used for wound treatment.  Voronezh State University researchers have explored the use of ficin to treat biofilms formed by Staphylococcus.   Ficin is an enzyme derives from figs latex and belongs to a family of proteases that also includes papain derived from papaya latex and bromelase extracted from pineapple stem.  The advantage of a plant enzyme is less allergenic and cytotoxic compared to bacterial or animal proteins.

ReCell to Accelerate Healing of Donor Sites

Avita, a regenerative medicine company focused on the treatment of wounds and skin defects, is using its ReCell medical device to promote healing and minimize scarring.  A small sample of skin is first collected from an area of normal skin. While the clinician prepares the affected area to be treated, the sample is processed using ReCell to generate a "spray suspension" (or RES – Regenerative Epithelial Suspension) of healthy skin cells. This suspension, containing all the necessary elements for the promotion of skin growth and regeneration, is then sprayed by the clinician onto the wound to be treated.  The company presented data from 2 trials conducted at leading burns centers across the United States, including successful results from its pivotal trial needed for premarket approval with the Food and Drug Administration. Results of the latest randomized controlled trial involving 106 patients who received skin grafts showed that ReCell accelerated healing of split-thickness donor sties by 30.7%. The median time to complete reepithelialization was 9.0 days in the ReCell-treated group, compared with 13.0 days in the control group treated with hydrocolloid dressings.