What is the appropriate management for a 4 cm full thickness laceration on the forehead with jagged borders and visible subcutaneous fat?

Management of 4 cm Full-Thickness Forehead Laceration with Jagged Borders and Visible Subcutaneous Fat

This wound requires thorough irrigation, debridement of devitalized tissue including exposed subcutaneous fat, layered closure with deep dermal sutures followed by superficial skin sutures, and close monitoring for infection given the contamination risk.

Wound Preparation and Debridement

Debridement of the visible subcutaneous fat is necessary to remove devitalized tissue that could serve as a medium for bacterial growth 1. The jagged borders also require careful debridement to create clean, viable wound edges that can be properly approximated 1.

• Irrigate the wound copiously with tap water under pressure—potable tap water is as safe as sterile saline and does not increase infection risk 2
• Remove all devitalized tissue, foreign debris, and contaminated fat to reduce bacterial load 1
• Debride jagged edges conservatively to create smooth, viable margins while preserving as much tissue as possible 3

Anesthesia

• Apply topical anesthetic (LET solution: lidocaine, epinephrine, tetracaine) directly to the wound for 10-20 minutes until edges appear blanched 1
• Supplement with buffered lidocaine injection using a small-gauge needle (maximum dose 5 mg/kg) 1
• Local anesthetic with epinephrine up to 1:100,000 concentration is safe for facial wounds 2

Closure Technique

Layered closure is essential for this full-thickness laceration—the dermis provides the wound's tensile strength, not the epidermis or subcutaneous fat 3.

Deep Layer Closure

• Close the subcutaneous layer first with absorbable sutures to eliminate dead space and reduce tension on the skin 3
• Fat and muscle do not hold sutures well, so focus approximation on the dermal layer 3
• Accurately approximate the entire depth of the dermis to the opposite dermis—this is where the skin's greatest strength lies 3

Superficial Layer Closure

• Use interrupted subcuticular sutures or monofilament nylon for the epidermis 4
• For facial wounds, consider absorbable sutures to avoid the trauma of suture removal 1
• Ensure precise coaptation of skin edges with slight eversion and no tension 4
• Tissue adhesive alone is NOT appropriate for this wound—it is only suitable for low-tension, superficial lacerations, not full-thickness wounds with exposed fat 2, 5

Why Secondary Intention Healing is Inappropriate

Closure by secondary intention is NOT recommended for this wound 6. Secondary intention healing should be reserved for specific surgical scenarios (such as after tumor excision where margins need confirmation) or contaminated wounds where primary closure would trap infection 6. This traumatic laceration on the cosmetically sensitive forehead requires primary closure for optimal functional and aesthetic outcomes 2, 5.

Post-Closure Management

• Apply occlusive or semiocclusive dressing—wounds heal faster in moist environments 2
• Monitor for signs of infection: increasing erythema, warmth, pain, or purulent drainage 1
• Consider follow-up within 48-72 hours to assess for early infection 1
• Keep wound clean and dry until suture removal 1
• Remove sutures in 5-7 days for facial wounds to minimize scarring 2

Common Pitfalls to Avoid

• Do NOT use tissue adhesive alone—it cannot adequately close full-thickness wounds with exposed subcutaneous tissue 2, 5
• Do NOT leave exposed fat undebrided—this increases infection risk significantly 1
• Do NOT allow secondary intention healing—this will result in prolonged healing, worse scarring, and potential complications on the forehead 6, 4
• Do NOT skip layered closure—single-layer closure of full-thickness wounds leads to poor cosmetic outcomes and wound dehiscence 3