Partial Thickness Wounds: The Middle Child of Injuries

Your skin is the largest organ in your body, accounting for 16% of your total body weight. It is critical in maintaining homeostasis and protects you against the external environment. Thus, one requirement of staying healthy is keeping your skin intact. Skin can be injured by wounds produced by trauma, burns, diseases, or surgery. These injuries can create disability and place a burden on health care systems.

Small acute wounds often heal without the intervention of health care professionals. The body’s own cellular responses, matrix remodeling, and growth factors efficiently manage the recovery of small wounds. However, larger skin injuries and chronic wounds tend to heal slowly. . These injuries make the patient susceptible to infection and fluid loss. These wounds particularly when chronic, can have serious consequences. Diabetic foot ulcers alone account for a mortality comparable to that of cancer.

Thus, treating partial-thickness wounds remains an enormous challenge for all healthcare professionals. There have been several advances to improve their care, specifically involving smart dressings and the use of technology.

How Deep Is That? Assessing Partial Thickness Wounds

Partial thickness wounds, often referred to as superficial wounds, involve damage to the outer layer of the skin, known as the epidermis, and may extend intothe dermis. This distinguishes them from full-thickness wounds, which extend throughthe dermis. Partial thickness wounds typically result from minor injuries like superficial cuts, abrasions, or first-degree burns. Common symptoms of partial thickness wounds include redness, mild swelling, and pain.

Diagnosis and assessment of partial thickness wounds are similar to those of superficial ones. Clinical evaluation and observation are essential to assess wound appearance, depth, and surrounding tissue. Imaging technologies are now available, making assessing the depth of these wounds more accurate.

High-frequency ultrasound and optical coherence tomography are valuable tools in assessing the depth of these wounds. Studies have shown that laser Doppler imaging (LDI) can accurately characterize partial thickness burns with over 90% accuracy, which reduces the need for invasive biopsies. The high-resolution imaging of the wound allows clinicians to make better decisions regarding treatment strategies.

Improved diagnosis of the wound depth influences treatment decisions. A miscalculation of the depth can result in inappropriate interventions, delayed healing, and an increased risk of complications. Furthermore, these noninvasive tools allow for intermittent monitoring during the healing process.

Treatment Approaches

Conservative Management

As with all wounds, cleansing  and debridement are essential steps to remove debris and damaged tissue, creating a more effective environment for healing. Recent research has shown that gentler debridement methods, such as hydrosurgical debridement, offer more precise tissue removal and minimize trauma to the healthy tissues. This process involves using pressurized saline while vacuuming the debrided contents.

As wound healing has developed, so have the dressings used to treat them. Traditional dressings, also known as inner dressings, such as gauze and cotton pads, are the most widely used clinical dressings due to their low cost. However, they have many disadvantages, including their inability to maintain the moisture level of the wound and their tendency to adhere  to the granulation tissue.

Modern dressings, however, cover the wound and accelerate the healing process. They offer better moisture retention, reduce pain, and improve the healing environment, including several that do not stick to granulation tissue. The most commonly used dressings in clinical practice are hydrogels, hydrocolloids, alginates, foams, and films.

1. Hydrogels: These dressings have a three-dimensional structure and are composed of hydrophilic substances. They have several advantages: they are insoluble in water, maintain wound moisture, are transparent, and allow easier wound monitoring. They are often used on pressure injuries, surgical wounds, and burns. They are best with wounds that have a minimal amount of exudate.
2. Hydrocolloids: These are also waterproof and excellent for maintaining moisture levels. They have an inner layer of gel-forming agents, which can include carboxymethylcellulose, gelatin, and pectin. This layer promotes healing by absorbing exudate.
3. Sodium alginate (SA) dressings:  Derived from seaweed, these dressings form a gel after binding to wound exudate. With this property, they are excellent in wounds requiring exudate absorption. As a result, they are not recommended for treating dry wounds or those with minimal exudate.
4. Foam dressings: These are semipermeable, either hydrophilic or hydrophobic, and have a bacterial barrier. Like sodium alginate dressings, they work well with moderate-to-high amounts of wound exudate. They also provide thermal insulation and maintain moisture levels. 
5. Film dressings: These polyurethane dressings are adhesive, porous, and thin. Oxygen, carbon dioxide, and water pass through the dressing; however, bacteria stay out of the wound. They also have automatic debridement properties and are best suited for superficial wounds with low exudate.

Pain management can be especially difficult for these wounds. Traditional medications such as over-the-counter analgesics and narcotics have proven to be of limited use, with addiction proving to be a serious potential side effect of narcotic use. 

Topical lidocaine has been used for years to help manage discomfort. One drawback is that the relief lasts only a few hours and requires multiple daily applications. However, one study using 4% lidocaine in a hydrogel dressing provided pain relief for multiple days after one dressing application. 

Advanced Therapies for Partial Thickness Wounds

Not all wounds heal adequately with conservative treatment. For those requiring advanced treatment, negative pressure wound therapy, hyperbaric oxygen therapy, and growth factor applications are the most common types.

Negative pressure wound therapy  

Negative pressure wound therapy (NPWT) continues to be a valuable tool in managing partial-thickness wounds, particularly those with moderate to high exudate levels. Several studies have shown that NPWT can shorten healing time compared to standard dressings. 

Hyperbaric oxygen therapy

Hyperbaric oxygen therapy (HBOT) has shown promise in accelerating wound healing, especially in patients with compromised tissue perfusion. Recent research has focused on optimizing HBOT protocols to maximize efficacy while minimizing the risk of oxygen toxicity. Promising results have been seen in using HBOT to improve healing in diabetic patients with partial-thickness wounds.

Growth factor applications

Growth factor and stem cell therapies represent the cutting edge of regenerative medicine in wound care. A study published in 2022 evaluated the use of epidermal growth factor (EGF) in a delivery system using biodegradable nanoparticles. The process showed sustained release of EGF over 14 days, significantly accelerating re-epithelialization. 

Surgical Interventions

While many partial-thickness wounds heal with conservative management or advanced therapies, some may require surgical intervention. Skin grafting techniques may be used for difficult wounds, including the use of split-thickness and full-thickness grafts and hydrosurgery. 

Complications and How to Treat Them

Infection

Wound treatment aims to avoid infection, regardless of location or depth. Risk factors include immunocompromised patients and inadequate wound hygiene. Prevention focuses primarily on a clean wound environment, antimicrobial dressings, and patient education.

Recently, the use of a smart hydrogel dressing was evaluated in a 2024 study. This dressing is embedded with pH-responsive nanoparticles, which only releases antibiotics in the presence of bacterial colonization. This offers a potential solution to reducing the risk of antibiotic resistance.

Delayed Healing

Delayed healing can result from the same factors as infection itself, as described above. Chronic diseases increase the risk of delayed healing, and some, like diabetes, may also raise infection risk. Managing any underlying diseases, like diabetes, in addition to proper wound care, is necessary to reduce the risk of delayed healing.

The use of extracellular vesicles (EVs), derived from mesenchymal stem cells, was studied in 2023 by applying these topically. Preliminary results in a diabetic wound model showed improved wound closure rates and angiogenesis.

Scarring

Scarring often manifests as hypertrophic or keloid formation in partial-thickness wounds. Currently, scar management techniques use a combination of techniques, including silicone-based products, pressure therapy, and intralesional corticosteroid injections.

A wearable mechanotherapy device in burn patients, which applies cyclic stress to healing wounds, has significantly reduced scar formation and improved the overall aesthetic appearance. 

Recent Research and Innovations 

Dressing Changes

Moving away from inert dressings, today’s dressings are capable of much more than merely covering the wound. Smart dressings with embedded sensors can monitor wound pH, temperature, and bacteria levels—all in real-time. The ability to detect and respond to infection and personalize treatment programs is a huge gain for wound therapy.

Nanofiber-based wound dressings, which mimic an extracellular matrix and promote cell proliferation, have been paired with silver particles and growth factors, promoting improved healing compared to traditional dressings.

Regenerative Medicine

Exosome therapy is a promising tool in regenerative medicine for wound healing. These extracellular vesicles can deliver therapeutic molecules to wound sites. In a clinical study involving partial thickness burns, exosomes accelerated wound healing and enhanced angiogenesis.

3D bioprinting of skin substitutes represents another frontier in wound care. Researchers reported in 2024 on a novel 3D bioprinting technique that allows for creating full-thickness skin constructs complete with hair follicles and sweat glands. While still in the preclinical stages, this technology holds immense promise for treating extensive partial-thickness wounds and burns.

Gene Therapy and CRISPR Technology

Gene therapy shows promise in wound healing for diabetics. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is one of the main tools used for gene therapy at the moment. Using CRISPR-based therapy targeting the factor 1-alpha gene, angiogenesis and wound closure were accelerated.

Synthetic biology has created a “living” dressing using genetically engineered bacteria capable of sending wound pH and producing growth factors as needed. 

Artificial Intelligence in Wound Care

Artificial intelligence (AI) is increasingly being integrated into wound care practice. A 2022 study demonstrated the efficacy of an AI-powered smartphone app in accurately assessing wound healing progress and predicting healing outcomes based on wound images. These AI-powered wound assessment platforms  have the potential to not only reduce health care costs but also the burden on healthcare workers and those who care for patients at home and in residential care facilities.

Machine learning algorithms are being developed to assist in identifying high-risk patients prone to wound complications. A 2024 study using an AI model demonstrated 85% accuracy in identifying those with potential problems, allowing for earlier intervention.

Partial Thickness Wounds: Skin-Deep Wounds With Sci-Fi Solutions

Recent years have shown promise in treating partial-thickness wounds. Instead of the “one size fits all” approach of the past, studies have repeatedly demonstrated that tailoring treatments to patients and wound profiles offer better results. Emerging technologies such as AI-assisted decision-making systems, 3D printing, and gene therapies all present new and exciting methods and approaches for treating these wounds.