1. What is Body Surface Area (BSA) Calculation for Eczema?

Definition: This calculator estimates the percentage of body surface area affected by eczema using the palm method (1 palm ≈ 1% BSA).

Purpose: It helps healthcare professionals and patients assess the severity and extent of eczema coverage on the body.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \%BSA \) — Percentage of body surface area affected
• Each body region is estimated as a percentage of total BSA

Explanation: The patient's palm (including fingers) represents approximately 1% of their total body surface area. Affected areas are summed to get total %BSA affected.

3. Importance of BSA Calculation in Eczema

Details: BSA assessment helps determine eczema severity, guide treatment decisions, and monitor disease progression or treatment response.

4. Using the Calculator

Tips: Enter the percentage affected for each body region. Typical adult BSA distributions:

• Head: ~9%
• Each arm: ~9% (total 18% for both arms)
• Trunk (front and back): ~36%
• Each leg: ~18% (total 36% for both legs)

5. Frequently Asked Questions (FAQ)

Q1: Why use the palm method for BSA calculation?
A: The palm method provides a quick, practical estimate without requiring complex measurements or calculations.

Q2: How accurate is this method?
A: It provides a reasonable estimate for clinical purposes, though more precise methods exist for research settings.

Q3: Does this differ for children?
A: Yes, children have different BSA distributions (larger head proportion). Use pediatric-specific calculators for children.

Q4: What BSA percentage indicates severe eczema?
A: Generally, >10% BSA in children or >20% in adults is considered moderate-to-severe, but clinical assessment is also important.

Q5: Can I use this for other skin conditions?
A: Yes, the palm method can be used for psoriasis, burns, or other dermatological conditions affecting body surface area.