Skin breakdown is a medical term describing the loss of healthy, intact skin, ranging from a superficial scratch to a deep, open wound. This damage occurs when the skin’s natural protective barrier is compromised, making it susceptible to injury. The most serious form is often associated with individuals who have limited mobility, such as those confined to a bed or wheelchair. Understanding the mechanisms of this injury is key to effective prevention and maintaining skin health.
Defining Skin Breakdown and Associated Terminology
The general phrase “skin breakdown” describes any injury that disrupts the skin’s integrity, but healthcare professionals use more precise terminology. The most widely accepted clinical term for injuries resulting from sustained external forces is a pressure injury. This term replaces older names like “pressure ulcer” or “bedsore,” as not all pressure-related damage results in an open ulcer. A pressure injury is defined as localized damage to the skin and underlying soft tissue, typically occurring over a bony prominence.
Mechanical Forces That Damage Skin Integrity
Skin integrity is most often damaged by four distinct mechanical forces: pressure, shear, friction, and moisture. Pressure is the vertical force that compresses soft tissue between a bony prominence and an external surface, like a mattress or chair. This compression squeezes small blood vessels, leading to ischemia (lack of blood flow), which deprives the tissue of oxygen and nutrients. If this pressure is not relieved, cells begin to die, causing tissue damage beneath the skin’s surface.
Shear is a parallel or horizontal force that causes the internal layers of tissue to slide over each other in opposite directions. This commonly occurs when a person slides down in a bed with the head elevated, where the skeleton moves down but the skin remains stuck to the sheet. This sliding motion stretches and tears the small blood vessels, which can lead to deeper tissue damage even at lower pressure levels. Friction, in contrast, is the rubbing of the skin’s surface against an external surface, such as being dragged across a bed sheet, and typically results in superficial abrasions.
Moisture significantly increases the skin’s vulnerability to mechanical forces, a process known as maceration. Prolonged exposure to fluids like sweat, urine, or wound drainage softens and weakens the outer layer of the skin. This softened skin is more easily damaged by friction and shear, making it prone to tearing. Managing excess moisture is a preventive measure that supports the skin’s natural protective function.
Classifying the Severity of Skin Injuries
Pressure injuries are classified using a standardized staging system that describes the depth and extent of the tissue damage. The first sign is a Stage 1 pressure injury, where the skin is intact but displays persistent, non-blanchable redness in a localized area. “Non-blanchable” means the redness does not temporarily turn white when light pressure is applied, indicating damage to the underlying capillaries. This initial stage may also present with changes in skin temperature or firmness compared to the surrounding area.
A Stage 2 pressure injury involves partial thickness skin loss, affecting the top layer (epidermis) and possibly part of the second layer (dermis). This stage appears as a shallow open ulcer with a pink or red wound bed, or as an intact or ruptured serum-filled blister. Progression to a Stage 3 injury involves full thickness skin loss, where fat tissue is visible but muscle, tendon, or bone are not exposed. The injury may look like a deeper crater.
The most severe category is a Stage 4 pressure injury, which features full thickness tissue loss with exposed muscle, tendon, ligament, cartilage, or bone. This injury often includes tunneling or undermining, where the wound edges extend beneath the surface skin.
Other Classifications
Two other classifications exist for less visible or obscured injuries: Deep Tissue Injury (DTI) and Unstageable. A suspected DTI presents as a localized area of persistent non-blanchable deep red, maroon, or purple discoloration, indicating damage to the deeper soft tissue beneath intact skin. An Unstageable pressure injury is one where the full extent of the tissue loss cannot be determined because the base of the wound is completely covered by dead tissue. This dead tissue may appear as yellow, tan, gray, green, or brown slough, or a hard, black eschar.
Simple Strategies for Skin Maintenance and Prevention
Preventing skin breakdown centers on minimizing the forces and factors that cause tissue damage. For individuals with limited mobility, regular repositioning is a highly effective strategy to relieve sustained pressure on bony areas and restore blood flow. Proper lifting techniques that avoid dragging the skin across surfaces are also necessary to minimize friction and shear forces.
Moisture Management and Nutrition
Effective skin care involves diligent management of moisture and hygiene using gentle, pH-balanced cleansers. Keeping the skin clean and dry, particularly in areas prone to incontinence, is important for preventing maceration. Applying a protective moisture barrier cream can provide a shield against wetness. Maintaining adequate hydration and a diet rich in protein and calories provides the nutritional building blocks required to maintain skin integrity and repair tissue.