A Deep Tissue Injury (DTI) is a serious form of pressure-induced damage that occurs in the deeper layers of soft tissue, often near the bone, before affecting the surface of the skin. DTIs are a significant concern for individuals with limited mobility. The injury involves damage to underlying structures, including muscle and subcutaneous tissue. The defining characteristic is that this deep damage happens under skin that may still appear intact or only slightly damaged.
Identifying the Deep Tissue Injury
The external appearance of a DTI often does not reflect the severity of the damage below the surface. A DTI typically manifests as a persistent, localized area of discoloration that is deep red, purple, or maroon. Unlike a temporary bruise, this discoloration often does not blanch, meaning it does not turn white when light pressure is applied.
The skin overlying the injury may remain intact, or it can present as a blood-filled blister, signifying separation of the epidermal layer. When palpated, the affected area often feels different from the surrounding healthy tissue. The tissue may be mushy, firm, or boggy to the touch, or feel noticeably warmer or cooler than the adjacent skin.
Identifying a DTI is challenging in individuals with darker skin tones, as the signature purple or maroon color may be difficult to see visually. In these cases, assessing the difference in tissue temperature and texture compared to nearby areas becomes a more important diagnostic indicator. Early recognition is important, as the subtle initial signs conceal the fact that significant, irreversible damage may have already occurred in the deeper muscle layers.
How Internal Tissue Damage Occurs
Deep Tissue Injuries result from a combination of mechanical forces that compromise the tissue’s ability to sustain life. The primary external factors are intense or prolonged pressure and shear forces acting on the body, particularly over bony prominences like the heels and sacrum. Pressure compresses the capillaries, leading to a reduction or complete blockage of blood flow, a condition known as ischemia.
Muscle and fat tissues near the bone are the most susceptible to this damage, as they receive the highest concentration of mechanical stress. This sustained lack of oxygen and nutrients causes cellular death, or necrosis, in these deep layers before the damage is visible on the skin’s surface. Shear forces also contribute, occurring when the skin stays fixed while underlying tissues shift, distorting and tearing small blood vessels.
This mechanical deformation of cells can cause damage within minutes, while the resulting ischemic damage from blood vessel occlusion takes several hours to fully develop. When pressure is finally relieved and blood flow returns, a reperfusion injury can occur. The sudden influx of oxygen creates a burst of inflammation and oxidative stress that further damages the already weakened tissue. This “inside-out” mechanism means the most extensive destruction is located deep beneath the surface, making treatment difficult.
Clinical Progression and Outcomes
The clinical course of a Deep Tissue Injury is often characterized by a rapid and unpredictable progression. DTIs are inherently unstable because the extent of the underlying damage is unknown at the time of initial discovery. The injury is caused by deep, irreversible tissue death that has already occurred, and the skin’s initial appearance is simply a delayed reflection of that internal event.
In many cases, the DTI will rapidly deteriorate, leading to the breakdown of the overlying skin to reveal the full extent of the tissue loss. This rapid evolution can transform the injury into an unstageable wound or a Stage 3 or Stage 4 pressure injury within days. The lag between the initial pressure event and the appearance of the purple discoloration can be up to 48 hours, and the skin may break down within another 24 hours.
Not all DTIs deteriorate; some injuries, especially if small and promptly relieved of pressure, may resolve over time. A significant majority of DTIs heal, but up to 27% may still progress to full-thickness tissue loss. The trajectory of the injury is determined by the initial magnitude of the tissue damage and the effectiveness of immediate interventions.
Initial Management Strategies
The initial response to a suspected Deep Tissue Injury must focus on immediately removing all pressure from the affected area to prevent further cellular damage. Repositioning the individual is the most important first step, ensuring that the injured site is completely offloaded and avoiding the use of donut-type devices. The goal is to restore blood flow and stop the progression of the injury.
Continuous monitoring of the discolored area is necessary to track any changes in size, color, or texture, as the injury can rapidly worsen. Supportive measures, including optimizing the patient’s nutritional status, are important to provide the body with the resources needed for tissue repair. A healthcare professional must be consulted immediately for a formal evaluation and to develop a comprehensive wound care and treatment plan.