What is the difference between stage I and stage II pressure ulcers?

Difference Between Stage 1 and Stage 2 Pressure Ulcers

Stage 1 pressure ulcers present with intact skin and non-blanchable erythema over a bony prominence, while Stage 2 pressure ulcers involve partial-thickness skin loss with exposed dermis but no deeper tissue exposure. 1

Stage 1 Pressure Ulcer Characteristics

Skin Integrity:

• The skin remains completely intact with no break in the epidermis 2, 3
• This is the defining feature that distinguishes Stage 1 from Stage 2 1

Color Changes:

• Non-blanchable erythema is the hallmark presentation in 75% of cases 2
• The affected area does not blanch (turn white) when pressed, though research shows blanching can sometimes be present contrary to traditional teaching 2
• In darkly pigmented skin, the area may appear normal in color in 11.4% of cases, making visual assessment alone insufficient 2

Temperature Differences:

• The affected area may be warmer or cooler than adjacent skin 4
• Cool areas (average -1.2°C compared to surrounding skin) are 31.8 times more likely to progress to tissue necrosis than warm areas 4
• This temperature difference is a critical early warning sign that visual inspection alone may miss 4

Texture and Sensation:

• The area may feel boggy, indurated (firm), or painful to touch 2
• These tactile findings are particularly important in darkly pigmented skin where color changes may be subtle 2, 5

Dermoscopic Features:

• When examined with dermoscopy, Stage 1 ulcers show petechial dots and telangiectatic streaks in 90% of cases 6
• These microscopic vascular changes persist under compression and help confirm the diagnosis 6

Stage 2 Pressure Ulcer Characteristics

Skin Integrity:

• Partial-thickness skin loss with exposed dermis is the defining feature 1
• The epidermis is broken, creating a visible wound 3
• The wound bed is viable, pink or red, and moist 3

Wound Appearance:

• Presents as a shallow open ulcer without slough or eschar 3
• May also present as an intact or ruptured serum-filled blister 3
• The dermis is visible but deeper tissues (subcutaneous fat, muscle, tendon, bone) are not exposed 1

Surrounding Skin:

• May have erythema extending beyond the wound edges 6
• Dermoscopic examination of this surrounding redness shows the same petechial dots and telangiectatic streaks seen in Stage 1 ulcers 6

Critical Clinical Distinctions

The Progression Pathway:

• Stage 1 represents the earliest detectable tissue damage with intact skin acting as a protective barrier 3
• Once the skin breaks and dermis is exposed, the ulcer has progressed to Stage 2 1
• This distinction is crucial because Stage 2 ulcers require different wound care approaches including appropriate dressings 7

Management Implications:

• Stage 1: Focus on immediate pressure relief with repositioning every 2-4 hours, advanced static air mattresses, and preventing progression 7, 8
• Stage 2: Apply hydrocolloid or foam dressings (changed every 1-7 days based on exudate) in addition to all Stage 1 interventions 7
• Both stages benefit from protein supplementation (30 energy percent protein) to support tissue healing 7

Common Pitfalls to Avoid

Assessment Errors:

• Do not rely solely on visual inspection for non-blanchable erythema, especially in darkly pigmented skin where color changes may be absent or subtle 2, 5
• Always assess temperature differences and tactile changes (bogginess, induration, pain) as these may be the only detectable signs in dark skin 2, 4
• Do not assume all intact skin with discoloration is Stage 1—cool temperature combined with non-blanching indicates high risk for progression to deep tissue injury 4

Documentation Requirements:

• Specify the anatomic location (e.g., sacrum, heel) and document all findings including color, temperature, texture, and patient symptoms 1
• For Stage 2, document wound dimensions, exudate characteristics, and surrounding skin condition 1

Staging Limitations:

• Do not attempt to stage wounds covered by eschar or slough—these must be classified as "unstageable" until debrided 1
• The presence of a blister does not automatically mean Stage 2; intact serum-filled blisters over pressure areas are classified as Stage 2, but blood-filled blisters may indicate suspected deep tissue injury 3