How is BSA estimated in psoriasis?

The patient's palm (excluding fingers) approximates 0.5% BSA, or with fingers approximately 1% BSA. BSA >10% typically indicates moderate-to-severe psoriasis. Combined with PASI and DLQI, it forms the three-measure assessment for biologic eligibility.

When does BSA indicate biologic therapy eligibility?

BSA >10% alone, or BSA >10% + DLQI >10 (rule of tens), or PASI >10 + DLQI >10 typically meets eligibility criteria for biologic therapy per NICE, BAD, and international guidelines.

BSA Psoriasis Body Surface Area

Estimate the body surface area affected by psoriasis using the palm method (patient's palm ≈ 1% BSA) to quickly quantify disease extent for treatment decision making.

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Related Calculators

PASI

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DLQI

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NAPSI

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BSA Psoriasis Body Surface Area

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Frequently Asked Questions

How is BSA estimated in psoriasis?

When does BSA indicate biologic therapy eligibility?