Body Surface Area Calculator For Psoriasis

BSA Calculation Formula:

\[ \%BSA = \text{Sum of affected areas (palm method: 1 palm ≈ 1\%)} \]

%BSA (percentage):

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1. What is Body Surface Area Calculation for Psoriasis?

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

Purpose: It helps dermatologists and patients assess psoriasis severity by quantifying the extent of skin involvement.

2. How Does the Calculator Work?

The calculator uses the palm method formula:

\[ \%BSA = \text{Number of affected palms} \]

Where:

\( \%BSA \) — Percentage of body surface area affected
1 palm ≈ 1% of total body surface area

Explanation: The patient's palm (including fingers) represents approximately 1% of their total body surface area.

3. Importance of BSA Calculation in Psoriasis

Details: BSA assessment helps determine disease severity, guide treatment decisions, and monitor treatment response over time.

4. Using the Calculator

Tips: Count the number of palm-sized areas affected by psoriasis and enter this number. The result shows the estimated percentage of BSA affected.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is the palm method?
A: It provides a quick estimate. For precise measurement, healthcare providers may use more detailed methods like the Rule of Nines.

Q2: What does the BSA percentage indicate?
A: Generally: <3% = mild, 3-10% = moderate, >10% = severe psoriasis, though other factors are also considered.

Q3: Should I include partially affected palms?
A: Yes, estimate fractions (e.g., 0.5 for half a palm) for more accuracy.

Q4: How often should BSA be measured?
A: Regular assessments help track disease progression or improvement, especially when starting new treatments.

Q5: Does this work for children?
A: The palm method can be used, but children have different body proportions so interpretation may differ.