What is the best type of Unna boot (compression bandage) for a patient with xylazine-induced wounds and a history of substance abuse, potentially complicated by skin and soft tissue infections?

Unna Boot Use in Xylazine Wounds: Not Recommended

Unna boots (zinc oxide compression bandages) are not appropriate for xylazine-associated wounds and should be avoided. The current evidence-based approach for these wounds emphasizes nonadherent, absorptive dressings with antimicrobial ointment rather than compression therapy 1.

Why Unna Boots Are Contraindicated

Xylazine wounds require a fundamentally different approach than traditional venous ulcers. These wounds present with unique characteristics that make compression bandaging problematic:

• Necrotic tissue progression: Xylazine wounds start as small ulcers but rapidly progress to deeper necrotic wounds with a distinctive "Swiss cheese" pattern of tissue loss surrounded by viable tissue 1
• Cytotoxic mechanism: The wounds result from direct cytotoxicity and peripheral vasoconstriction, not venous insufficiency 1
• High exudate production: These chronic wounds produce significant drainage requiring absorptive capacity 1

Evidence-Based Wound Care Protocol

The recommended approach uses nonadherent and absorptive dressings with antimicrobial ointment 1. This strategy allows for:

Core Treatment Components

• Conservative debridement: Perform surgical or enzymatic debridement cautiously, avoiding aggressive excision that exposes healthy tissue, tendons, or bone 1, 2, 3
• Antimicrobial coverage: Apply antimicrobial ointment directly to wound bed 1, 2
• Nonadherent primary dressing: Use materials that won't stick to the wound base and cause trauma during changes 1
• Absorptive secondary layer: Apply dressings that manage heavy exudate while maintaining moist wound environment 1, 2, 3

Critical Management Principles

Avoid aggressive surgical debridement, as this approach has been shown to impair healing, expose tendons and bone, lead to chronic osteomyelitis, and increase amputation risk 1, 2, 3. The conservative, tissue-preserving approach is superior 2, 3.

Do not close wounds prematurely. Split-thickness skin grafts should be delayed until patients are stabilized in substance use treatment, as ongoing drug injection into grafted areas leads to failure 1, 2.

Practical Wound Care Algorithm

Initial Assessment

• Measure wound dimensions and depth to detect bone involvement 3
• Assess for signs of deep space or necrotizing infection (the characteristic "Swiss cheese" pattern) 1
• Determine if hospitalization is needed for suspected deep infection 1, 2

Outpatient Management Strategy

• Cleanse with sterile normal saline only (avoid iodine or antibiotic solutions) 2, 3
• Perform conservative debridement of necrotic tissue without excising healthy margins 2, 3, 4
• Apply antimicrobial ointment to wound base 1, 2
• Cover with nonadherent primary dressing 1
• Add absorptive secondary layer for exudate management 1, 2
• Leave dressing undisturbed for minimum 48 hours unless leakage occurs 2

Follow-Up Protocol

• Monitor every 2-5 days initially in outpatient settings 3
• Re-evaluate at 2 weeks; if <50% area reduction, consider advanced therapies 3
• Document wound size, drainage quality/quantity, and surrounding tissue viability at each visit 3

Common Pitfalls to Avoid

Never apply compression therapy (including Unna boots) without understanding the underlying pathophysiology—these are not venous ulcers 1.

Do not perform aggressive debridement that removes viable tissue margins, as this creates worse outcomes including tendon exposure and osteomyelitis 1, 2, 3.

Avoid closing infected wounds—use approximation with Steri-Strips followed by delayed closure only after infection control 2.

Do not apply advanced therapies (skin substitutes, becaplermin) to actively infected wounds, as infection must be controlled first or treatment will fail 2, 3.

Special Considerations for This Population

These wounds heal slowly over weeks to months and require sustained engagement 1. Barriers include:

• Homelessness complicating access to scheduled wound care (40% of patients) 5
• High rates of leaving against medical advice (49-64% in surgical cases) 5
• Ongoing substance use during treatment (68% of surgical patients) 5
• Difficulty accessing wound care supplies 1

Optimize medication for opioid use disorder to decrease injection frequency and reduce exposure to xylazine-contaminated drug supply 6, 7.

The surgical complication rate for these wounds is 59%, primarily from continued wound issues, infections, and graft failures 5. This reinforces the importance of conservative, non-surgical management in outpatient settings with nonadherent, absorptive dressings rather than compression bandaging 1, 2, 8.