CLASI

Cutaneous Lupus Erythematosus Disease Area and Severity Index — Albrecht et al., 2005; severity bands Klein et al., 2011

Purpose
Physician-scored activity and damage of cutaneous lupus erythematosus (all subtypes), for monitoring and trial endpoints.
Population
Adults and children with CLE (ACLE, SCLE, CCLE) with or without SLE. Score the worst lesion in each area; LE tumidus, panniculitis and mucosal disease are better captured by the RCLASI.
Formula
Activity (0–70) = Σ 13 areas [erythema 0–3 + scale/hypertrophy 0–2] + mucous membrane 0–1 + recent hair loss 0–1 + inflammatory alopecia 0–3. Damage (0–56) = Σ 13 areas dyspigmentation 0–1 (×2 if it usually lasts ≥ 12 months) + Σ 12 areas scarring/atrophy/panniculitis 0–2 + scarring alopecia 0/3–6.
Severity thresholds
Activity 0–9 mild · 10–20 moderate · 21–70 severe (Klein 2011). Response: decrease ≥ 4 points or ≥ 20 %. No validated damage bands.
© The CLASI is copyrighted by the University of Pennsylvania (Victoria P. Werth). Clinical and academic use is permitted; commercial use requires a licence from Penn. The revised RCLASI (Kuhn 2010) adds oedema/infiltration and subcutaneous nodules and is not implemented here.
🔥 Activity — 13 anatomical areas

Score the most severe lupus lesion within each area. Groin lesions are scored under abdomen.

Erythema: 0 absent · 1 pink, faint erythema · 2 red · 3 dark red, purple/violaceous, crusted or haemorrhagic
Scale / hypertrophy: 0 absent · 1 scale · 2 verrucous / hypertrophic
Areas subtotal 0 / 65
👄 Mucous membranes and hair
Mucous membrane lesions: 0 absent · 1 lesion or ulceration (active, attributable to lupus)
Recent hair loss: 0 no · 1 yes — more hair loss than usual in the last 30 days, attributed to lupus (patient-reported)
Alopecia (clinically inflamed): 0 absent · 1 diffuse, non-inflammatory · 2 focal or patchy in one quadrant · 3 focal or patchy in more than one quadrant
Activity total 0 / 70
🩹 Damage — 13 anatomical areas

Scalp scarring is scored in the scarring-alopecia item, not in the scalp row.

Dyspigmentation: 0 absent · 1 present (hypo- or hyperpigmentation)
Scarring / atrophy / panniculitis: 0 absent · 1 scarring with loss of normal skin surface markings · 2 severely atrophic (depressed) scarring or lipoatrophy from resolved panniculitis
Areas subtotal 0 / 50
💇 Scarring alopecia
Scarring of the scalp: 0 absent · 3 in one quadrant · 4 in two quadrants · 5 in three quadrants · 6 in the whole scalp (four quadrants)
Damage total 0 / 56
📚 References
  1. Albrecht J, Taylor L, Berlin JA, et al. The CLASI (Cutaneous Lupus Erythematosus Disease Area and Severity Index): an outcome instrument for cutaneous lupus erythematosus. J Invest Dermatol. 2005;125(5):889–94.
  2. Klein R, Moghadam-Kia S, LoMonico J, et al. Development of the CLASI as a tool to measure disease severity and responsiveness to therapy in cutaneous lupus erythematosus. Arch Dermatol. 2011;147(2):203–8.
  3. Kuhn A, Meuth AM, Bein D, et al. Revised Cutaneous Lupus Erythematosus Disease Area and Severity Index (RCLASI): a modified outcome instrument for cutaneous lupus erythematosus. Br J Dermatol. 2010;163(1):83–92.
  4. Worm M, Zidane M, Eisert L, et al. S2k guideline: Diagnosis and management of cutaneous lupus erythematosus – Part 1: Classification, diagnosis, prevention, activity scores. J Dtsch Dermatol Ges. 2021;19(8):1236–47.
  5. O'Kane D, McCourt C, Meggitt S, et al. British Association of Dermatologists guidelines for the management of people with cutaneous lupus erythematosus 2021. Br J Dermatol. 2021;185(6):1112–23.
Clinical decision support only. This tool is intended to assist clinical assessment and does not replace professional judgment. Always interpret results in the context of the individual patient.