1. What is BSA Calculator For Psoriasis?

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

Purpose: It helps dermatologists and patients quantify psoriasis severity and track treatment progress.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• %BSA — Percentage of body surface area affected
• Each body part's affected percentage is estimated using the palm method (1 palm = ~1% of total BSA)

Explanation: The affected areas of different body parts are summed to get the total BSA involvement.

3. Importance of BSA Calculation in Psoriasis

Details: BSA measurement helps classify psoriasis severity:

• Mild: <3% BSA
• Moderate: 3-10% BSA
• Severe: >10% BSA

4. Using the Calculator

Tips: Estimate the percentage of each body part affected by psoriasis. Enter values between 0-100%. The total will automatically calculate.

5. Frequently Asked Questions (FAQ)

Q1: What is the palm method?
A: The patient's palm (including fingers) represents approximately 1% of their total body surface area.

Q2: How accurate is this method?
A: While not as precise as digital imaging, it provides a quick, practical estimate for clinical use.

Q3: What body areas should I assess?
A: Typically divide into head (4.5%), arms (9% each), trunk (36%), and legs (18% each).

Q4: How does this affect treatment decisions?
A: BSA is a key factor in determining whether to use topical, phototherapy, or systemic treatments.

Q5: Should I include unaffected skin between plaques?
A: No, only count the actual affected areas (plaques).