Cutaneous Lupus Erythematosus Disease Area & Severity Index (CLASI)

S

Ea

N

F

V

Ch

Ab

Ar

H

L

Ft

PNS

Bk

Region Abbreviation Legend

Body Regions Status

Not assessed

Active lesions

Completed (Normal or Damage only)

Assessment Progress: 0%

Patient Demographics (Optional)

Patient Name

Date of Birth

Age

Gender Prefer not to say Male Female Other

Anonymize data in exports and summary

All data remains in your browser until exported. Anonymizing removes name and DOB from exports and the summary box.

Current CLASI Scores

Activity: 0

Damage: 0

Severity – Mild

Date of evaluation ? Date when the assessment was performed

Please select a valid date

Mucous membrane involvement ? Oral or nasal ulceration present 0 – Absent 1 – Present

Recent hair loss (≤ 30 days) ? Increased hair loss in past month 0 – No 1 – Yes

Non-scarring alopecia ? Hair loss without permanent follicle destruction 0 – Absent 1 – Diffuse 2 – Focal ≤1 quadrant 3 – Focal >1 quadrant

Scarring alopecia ? Permanent hair loss with follicle destruction 0 – Absent 3 – One quadrant 4 – Two quadrants 5 – Three quadrants 6 – Whole scalp

Assessment Summary Automatically generated based on your inputs

Copy Results Export to Excel Reset

Developed by Dr. Ahmed Omar – RheumGuide.ca

Confirm Reset

Are you sure you want to reset all assessment data? This cannot be undone.

Cancel Reset

*This web tool was developed by Dr. Ahmed Omar for RheumGuide.ca (Ver 1 – May 2025). We welcome your feedback to help optimize its functionality—please use our contact form to share your suggestions and feedback.

*Please note that this web page is not optimized for mobile (e.g. cellphone) use. It is best used on a laptop or desktop computer. 

How to Calculate the CLASI Score
Cutaneous Lupus Erythematosus Disease Area & Severity Index
​
​The CLASI measures skin involvement in lupus by separating reversible activity from permanent damage.

Follow the four steps below to obtain the Activity Score (CLASI‑A) and the Damage Score (CLASI‑D).

Step 1 – Locate the 13 Body ZonesScalp; Ears; Nose & malar area; Rest of face; V‑neck / anterior neck; Chest; Abdomen; Arms; Hands; Legs; Feet; Posterior neck & shoulders; Back & buttocks.
Score only the worst lesion in each zone.

Step 2 – Calculate the Activity Score (CLASI‑A)Zone‑based items

• Erythema (0–3) 0 = none, 1 = light pink, 2 = red, 3 = dark red / violaceous
• Scale or hypertrophy (0–2) 0 = absent, 1 = fine scale, 2 = verrucous or hypertrophic
  (Maximum per zone = 5.)

Additional activity items

• Mucous‑membrane ulceration 0 = absent; 1 = present
• Recent hair loss (≤ 30 days) 0 = no; 1 = yes
• Non‑scarring alopecia of the scalp 0 = absent; 1 = diffuse thinning; 2 = focal loss ≤ 1 quadrant; 3 = focal loss > 1 quadrant

CLASI‑A = sum of
• erythema scores (all zones)
• scale/hypertrophy scores (all zones)
• mucous‑membrane score
• recent hair‑loss score
• non‑scarring alopecia score

Step 3 – Calculate the Damage Score (CLASI‑D)Zone‑based items

• Dyspigmentation (0 or 1) 0 = absent; 1 = present.
   If present ≥ 12 months, double that zone’s value.
• Scarring / atrophy / panniculitis (0–2) 0 = absent; 1 = loss of skin markings; 2 = depressed atrophy or lipoatrophy

Scalp‑specific item

• Scarring alopecia 0 = none; 3 = one quadrant; 4 = two; 5 = three; 6 = all four quadrants

CLASI‑D = sum of
• dyspigmentation scores (after doubling chronic sites)
• scarring / atrophy scores (all zones)
• scarring‑alopecia score

Step 4 – Interpret the Activity Score

• 0 – 9 → mild activity
• 10 – 20 → moderate activity
• 21 or higher → severe activity

(The damage score has no fixed bands; it represents cumulative, irreversible change.)

Practical Tips

• Record the worst lesion in each zone; if both front and back are involved, use the higher score.
• Double the dyspigmentation value only when color change has persisted for at least one year.
• Standardized diagrams or digital tools improve scoring consistency.
• Train scorers before use in trials or longitudinal care.

References

1. Klein RS, Bangert E, Furst DE et al. Reliability and validity of the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI). J Invest Dermatol. 2008;128:1327‑1332.
2. Albrecht J, Werth VP. The CLASI: a useful clinical index for lupus erythematosus. Dermatol Clin. 2010;28:525‑531.
3. CLASI Training Slides, University of Pennsylvania (accessed 2024).

Disclaimer and Privacy:
This tool is provided for informational and clinical documentation assistance only. It does not replace professional medical judgment or diagnostic evaluation. Always review and validate all findings before finalizing reports or treatment decisions. If patient information is entered, please ensure compliance with local privacy laws and guidelines (e.g., HIPAA). The anonymization feature is provided to help minimize the risk of patient identification in exported materials.


.