PASI — Psoriasis Area and Severity Index
Standard severity scoring for plaque psoriasis. PASI ≥10 typically indicates moderate-to-severe disease requiring systemic treatment.
Score interpretation
PASI <5: Mild psoriasis
→ Topical therapy (potent steroids, calcipotriol, coal tar); emollients; education
PASI 5–9.9: Moderate psoriasis
→ Optimise topicals; consider phototherapy (NB-UVB); dermatology referral
PASI ≥10: Moderate-to-severe psoriasis
→ Systemic therapy: methotrexate, ciclosporin, or acitretin; consider biologic (TNF/IL-17/IL-23 inhibitor) if PASI >10 with DLQI >10; dermatology referral
Interpretation bands for the PASI. Apply clinical judgement and local guidance.
References
- Fredriksson T, Pettersson U. Severe psoriasis — oral therapy with a new retinoid. Dermatologica. 1978;157(4):238-244.
Related
Curated clinical cross-links plus same-class fallbacks.
- Methotrexate (Dermatology — Psoriasis) · Disease-Modifying Antirheumatic / Immunosuppressant
- Ciclosporin · Systemic Immunosuppressant — Eczema / Psoriasis
- Salicylic Acid · Keratolytic — Warts / Psoriasis / Hyperkeratosis
- Ixekizumab · IL-17A Inhibitor — Psoriasis
- Guselkumab · IL-23 Inhibitor — Psoriasis
- Risankizumab · IL-23 Inhibitor — Psoriasis / Crohn's
- Suspicious Pigmented Lesion — Melanoma Pathway · NICE NG14 2015 / BAD
- Cellulitis and Erysipelas · NICE NG141 2019 / CREST
- Psoriasis — Severity Assessment and Step-Up Therapy · NICE NG153 2019 / BAD
- Atopic Eczema — Assessment and Step-Up Therapy · NICE NG95 2023
- Urticaria and Angioedema · BSACI / EAACI Guidelines 2022
- Acne Vulgaris — Grading and Treatment · NICE NG198 2021 / BAD
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.