Skin Integrity and Pressure Injuries

Vocabulary definitions covering skin anatomy, hair and nail conditions, dermatological lesions, and pressure injury classification stages.

Epidermis

The outer protective layer of skin that contains keratinocytes and melanocytes, has no blood vessels, and helps limit water loss and block pathogens.

Dermis

The connective tissue layer of skin containing blood vessels, nerves, hair follicles, and glands, which provides strength, sensation, and temperature control.

Subcutaneous tissue

The layer composed of fat and connective tissue beneath the dermis that cushions, insulates, and stores energy.

Pediculosis

A skin/scalp infestation involving lice or nits attached to hair.

Alopecia areata

A hair loss condition characterized by smooth patches of scalp hair loss.

Hirsutism

The presence of excess terminal hair growth.

Tinea capitis

A fungal scalp condition presenting as scaling accompanied by hair loss.

Onychomycosis

A fungal infection causing thick, discolored nails.

Paronychia

Inflammation of the skin surrounding the nail fold.

Clubbing

An increased nail angle accompanied by a bulbous fingertip, often serving as a cue for underlying perfusion or oxygenation concerns.

Cellulitis

An infectious skin condition characterized by spreading warmth, redness, swelling, and pain.

Common Skin Conditions Comparison

A diagnostic reference panel illustrating visual patterns for Atopic Dermatitis, Psoriasis, Cellulitis, Tinea Corporis, Scabies, and Melanoma.

ABCDE Melanoma Screen

A screening mnemonic for suspicious skin lesions: A — Asymmetry, B — Border irregularity, C — Color variation, D — Diameter (especially enlarging), and E — Evolving over time.

Primary Lesions

Initial physical skin changes classified by appearance, including macule/patch (flat color change), papule/plaque (raised solid lesion), vesicle/bulla (fluid-filled), pustule (purulent fluid), and nodule (deeper solid lesion).

Shear

A mechanical risk factor occurring when outer skin stays stationary while deeper tissue slides, commonly seen when the head of the bed is elevated.

Braden Scale

A standardized risk assessment framework organizing six risk subscales: sensory perception, moisture, activity, mobility, nutrition, and friction and shear.

Stage 1 Pressure Injury

Intact skin with localized non-blanchable erythema, where changes in pain, temperature, or firmness may precede visible color changes.

Stage 2 Pressure Injury

Partial-thickness skin loss with exposed dermis featuring a viable, pink/red, moist wound bed, or an intact or ruptured serum-filled blister.

Stage 3 Pressure Injury

Full-thickness skin loss in which adipose tissue and granulation may be visible, with possible undermining or tunneling, but without exposed fascia, muscle, tendon, cartilage, or bone.

Stage 4 Pressure Injury

Full-thickness skin and tissue loss with exposed or directly palpable fascia, muscle, tendon, cartilage, or bone.

Unstageable Pressure Injury

Full-thickness skin and tissue loss where slough or eschar obscures the true depth of the wound bed.

Deep Tissue Pressure Injury

Intact or non-intact skin presenting with persistent non-blanchable deep red, maroon, or purple discoloration, or epidermal separation revealing a dark wound bed or blood-filled blister.

Pressure Injury Stages Diagram

Cross-sectional representations demonstrating tissue involvement depth for Stage 1, Stage 2, Stage 3, Stage 4, Unstageable, and Deep Tissue Pressure Injury.