How is prurigo nodularis IGA graded?

PN IGA 0 (clear): no lesions. 1 (almost clear): lesions present but nearly flat, no or minimal erythema. 2 (mild): slightly elevated nodules, mild erythema. 3 (moderate): elevated nodules, moderate erythema/excoriation. 4 (severe): prominent nodules, severe erythema.

What biologics are FDA-approved for prurigo nodularis?

Dupilumab (anti-IL-4R, 2022) and nemolizumab (anti-IL-31RA, 2024) are FDA-approved for moderate-to-severe PN in adults. Both achieve IGA 0/1 in 40-50% of patients at week 24.

What is the pathophysiology of prurigo nodularis?

PN: chronic itch-scratch cycle with Th2/Th22 immune activation, IL-31 elevation, and peripheral/central sensitization. Associated with atopic dermatitis (AD) in 25-30% of patients. Type 2 inflammation drives both PN and AD.

Prurigo Nodularis IGA Severity

Assess prurigo nodularis (PN) severity using IGA 0-4 scale. IGA 0/1 response with >=2 grade improvement is the primary endpoint for dupilumab (LIBERTY-PN PRIME) and nemolizumab.

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