Burn Surface Area Calculation for Digits 2 and 3
The burn described involves approximately 2% of total body surface area (TBSA), calculated as roughly 80 thumbprints across both digits' dorsal and palmar surfaces from PIP joints to fingertips.
Calculation Method
The entire hand represents approximately 1% TBSA per the Lund-Browder method, which is the recommended standardized approach for measuring burned body surface area in both adults and children 1.
Breaking Down the Hand Surface Area
- Each complete digit (finger) accounts for approximately 42 thumbprints out of the total 80 thumbprints that comprise one entire hand 2
- One thumbprint represents approximately 1/30th of 1% TBSA, or roughly 0.033% 2
- Each digit surface (volar, dorsal, radial, ulnar) typically requires 2 thumbprints to cover, except for the volar middle and ring fingers which require 3 prints each 2
Specific Calculation for Your Burn
For the 2nd and 3rd digits from PIP to nail (distal two-thirds of each finger):
- Dorsal surface of digits 2 and 3 (PIP to nail): approximately 4 thumbprints per digit × 2 digits = 8 thumbprints
- Palmar surface of digits 2 and 3 (PIP to nail): approximately 4 thumbprints per digit × 2 digits = 8 thumbprints
- Total: approximately 16 thumbprints = roughly 0.5% TBSA 2
Clinical Significance
This burn requires immediate referral to a burn specialist or burn center because hand burns involving partial-thickness or full-thickness depth require specialized care beyond first aid to prevent functional disability 3.
Why This Matters
- Burns on function-sensitive areas like hands are considered severe regardless of TBSA percentage 1
- Deep burns in areas that might lead to functional sequelae (including hands) meet criteria for specialized burn center management in adults 1
- In children, deep burns in function-sensitive areas including hands require burn center evaluation 1
Immediate Management Priorities
- Cool the burn immediately with clean running water for 5-20 minutes to limit tissue damage and reduce pain 3, 4
- Remove any jewelry before swelling occurs to prevent vascular compromise 4, 5
- After cooling, loosely cover with a clean, non-adherent dressing while arranging immediate transfer 3
- Administer over-the-counter pain medications such as acetaminophen or NSAIDs 3, 4
Critical Pitfall to Avoid
Do not delay referral for any partial-thickness or full-thickness hand burn, as this leads to permanent functional impairment 3. The small TBSA percentage is irrelevant—the anatomic location on the hand makes this a severe burn requiring specialist care.