What are the differential diagnoses to consider in a patient presenting with an electrical burn?

Differential Diagnosis for Electrical Burns

The primary differential diagnoses for electrical burns include thermal burns (from arc flash or secondary ignition), radiation burns (particularly in mass casualty scenarios), chemical burns, and crush injuries with compartment syndrome—all of which can present with similar tissue destruction patterns but require distinct management approaches.

Key Distinguishing Features

Thermal Burns vs. Electrical Burns

• Thermal burns present immediately at the time of exposure with visible skin damage that correlates with injury depth, whereas electrical burns often have deceptively minimal surface findings despite extensive deep tissue destruction 1, 2.
• Arc burns can occur without direct contact with the electrical source but produce thermal injury patterns that may be confused with flame burns 2, 3.
• The presence of distinct entry and exit wounds is pathognomonic for electrical injury, unlike thermal burns which show continuous burn patterns 2.

Radiation Burns (Cutaneous Radiation Syndrome)

• Radiation burns do not present immediately after exposure—patients with thermal burns appearing immediately after an incident have thermal rather than radiation injury 4.
• The latent period is diagnostic: radiation burns show initial erythema, followed by a symptom-free interval of days to weeks, then manifest with desquamation, whereas electrical burns show progressive tissue destruction without a latent period 4.
• Radiation exposure causes systemic hematopoietic syndrome (lymphopenia, thrombocytopenia) and gastrointestinal symptoms (nausea, vomiting, diarrhea within hours) that are absent in isolated electrical burns 4.

Chemical Burns

• Chemical burns, particularly from agents like hydrofluoric acid, cause progressive tissue destruction but lack the characteristic entry/exit wound pattern of electrical injury 4, 5.
• Chemical burns require specific antidotes and decontamination protocols, whereas electrical burns require aggressive fluid resuscitation for myoglobin clearance 1, 6.

Crush Injury with Compartment Syndrome

• Both electrical burns and crush injuries can present with compartment syndrome, myoglobinuria, and rhabdomyolysis 2, 7.
• The key differentiator is mechanism of injury history: electrical contact versus mechanical compression 2.
• Electrical injuries require cardiac monitoring for arrhythmias (ventricular fibrillation, asystole, ventricular tachycardia), which is not a primary concern in isolated crush injuries 1, 3.

Critical Diagnostic Pitfalls

Underestimating Injury Severity

• The most dangerous error is judging electrical burn severity by visible skin damage alone—extensive deep tissue necrosis, particularly of periosseous muscle, commonly occurs with minimal surface findings 1, 5, 2.
• The volume conductor theory explains why extremity electrical burns cause worse deep tissue damage than torso burns despite similar surface appearance 2.

Cardiac Complications

• Failure to initiate cardiac monitoring can result in missed life-threatening arrhythmias, which are the primary cause of immediate death from electrocution 1.
• Both low-voltage and high-voltage currents can precipitate ventricular fibrillation, ventricular asystole, and ventricular tachycardia 1, 3.

Progressive Tissue Destruction

• Electrical burns demonstrate progressive tissue loss over hours to days due to small vessel occlusion and elevated arachidonic acid levels in areas of heat production 2.
• Technetium Tc 99m pyrophosphate uptake and serial muscle biopsies help determine nonviable tissue requiring debridement 2.

Essential Diagnostic Workup

Immediate Assessment

• Document voltage exposure (high-voltage >1000V vs. low-voltage <1000V), current type (AC vs. DC), duration of contact, and pathway through the body 2, 3.
• Assess for compartment syndrome by checking for tightness, swelling, burning pain, and distal neurovascular compromise—blue, purple, or pale extremities indicate poor perfusion requiring emergency escharotomy 5.

Laboratory Monitoring

• Obtain CPK levels, myoglobin, and renal function tests to assess for rhabdomyolysis 7.
• Monitor for elevated CPK as a risk factor for prolonged hospitalization (OR = 1.40) 7.

Cardiac Evaluation

• Continuous cardiac monitoring is mandatory for all electrical burn patients regardless of voltage 1, 3.
• Obtain baseline ECG to assess for arrhythmias or conduction abnormalities 3.

Management Implications Based on Diagnosis

Confirmed Electrical Burn

• Initiate aggressive fluid resuscitation with 0.9% saline to maintain urine output of 100 ml/hour to overcome destructive renal tubular effects of myoglobin and hemoglobin products 1, 2.
• All electrical burns in children and high-voltage electrical burns in adults require immediate burn center referral 1, 5.
• Consider early escharotomy within 48 hours if compartment syndrome develops, ideally performed at a specialized burn center 1, 6.

Alternative Diagnoses

• Thermal burns require cooling with running water for 5-20 minutes if TBSA <20% in adults or <10% in children without shock 5, 6.
• Radiation burns require hematopoietic support and management of gastrointestinal and systemic complications rather than immediate surgical intervention 4.
• Chemical burns require specific decontamination and antidote administration based on the causative agent 4, 5.