What's on my differential for a forehead laceration?

Differential Diagnosis for Forehead Laceration

A forehead laceration is not a diagnosis requiring a differential—it is a traumatic injury requiring assessment of mechanism, depth, contamination status, and associated injuries rather than alternative diagnostic considerations.

Understanding the Clinical Question

The term "differential diagnosis" applies to symptoms or presentations with multiple possible underlying causes. A forehead laceration is itself a traumatic injury with a known mechanism 1, 2. The clinical approach focuses on:

Key Assessment Parameters (Not Differential Diagnoses)

Wound Characteristics to Evaluate:

• Depth of injury: Superficial (epidermis only), partial thickness (into dermis), or full thickness (through dermis into subcutaneous tissue or deeper structures) 3, 2
• Contamination status: Clean versus contaminated wounds, which affects infection risk and closure timing 1, 4
• Time since injury: Facial wounds can be closed up to 24 hours post-injury due to excellent vascular supply 5, 1
• Wound edges: Linear with smooth margins versus stellate or irregular edges 6

Associated Injuries to Rule Out:

• Underlying fractures: Frontal bone or orbital rim fractures requiring radiographic evaluation if mechanism suggests significant force 3, 2
• Nerve injury: Assess facial nerve function, particularly supraorbital and supratrochlear nerve integrity 2
• Foreign bodies: Glass, gravel, or other debris requiring removal before closure 1, 3
• Deeper structure involvement: Periosteum, muscle, or galea involvement requiring layered closure 3

Critical Clinical Pitfalls

Common errors in forehead laceration assessment:

• Failing to perform adequate wound exploration to assess true depth and rule out foreign bodies 1, 2
• Missing associated injuries such as orbital fractures or globe injuries in high-impact mechanisms 2
• Assuming all facial lacerations require irrigation—clean, noncontaminated facial lacerations show no infection rate difference with or without irrigation 6
• Delaying closure unnecessarily—facial wounds tolerate closure up to 24 hours without increased infection risk 5, 1

Management Approach Based on Wound Assessment

For simple forehead lacerations:

• Use 5-0 or 6-0 monofilament non-absorbable sutures (nylon or polypropylene) for optimal cosmetic outcomes 5
• Remove sutures after 5-7 days to minimize scarring 5
• Layered closure is indicated for deeper wounds involving muscle or galea 5, 3

For contaminated or high-risk wounds:

• Reserve antibiotics for grossly contaminated wounds, involvement of deeper structures, or patient comorbidities (diabetes, immunosuppression) 4
• Thorough debridement is more important than antibiotic prophylaxis 5, 1