EASI Calculator (Eczema Area and Severity Index)
Enter severity (0–3; optional half points) and % area for each region. The tool calculates total EASI (0–72) and a severity band.
Inputs
The Eczema Area and Severity Index (EASI) is an investigator-assessed scoring system used to quantify the clinical signs and extent of atopic dermatitis (eczema). It’s widely used in clinical practice and especially in clinical trials because it gives a standardized way to track severity over time and response to treatment. PMC+2DermNet®+2
What EASI measures
EASI combines:
- Severity of 4 signs (each scored 0–3) in each body region:
- Erythema (redness)
- Induration/papulation (thickness/swelling)
- Excoriation (scratch marks)
- Lichenification (skin thickening) DermNet®+1
- Area involved in each region, converted to an area score (0–6) using standard % bands (0%, 1–9%, 10–29%, 30–49%, 50–69%, 70–89%, 90–100%). DermNet®+1
How it’s calculated (overview)
The body is divided into 4 regions: Head/Neck, Upper Limbs, Trunk, Lower Limbs.
For each region:
Region score = (sum of 4 sign severities) × (area score) × (region weighting)
Weightings depend on age group (commonly ≥8 years vs 0–7 years). The final EASI total is the sum of all region scores, ranging 0–72. DermNet®+1
Interpreting the score (common bands)
A commonly used interpretation is:
- 0 = clear
- 0.1–1.0 = almost clear
- 1.1–7.0 = mild
- 7.1–21.0 = moderate
- 21.1–50.0 = severe
- >50 = very severe PMC
