Calculator
Region multipliers — adult: head/neck ×0.1, upper limbs ×0.2, trunk ×0.3, lower limbs ×0.4 · under 8: ×0.2 / ×0.2 / ×0.3 / ×0.3.
Result
Health note: this is a severity index for clinical/research use, not a diagnosis. Eczema management should follow your dermatologist's advice.
Worked example
Adult (8+), verified against the reference implementation:
| Region | Signs sum | Area score | Multiplier | Region score |
|---|---|---|---|---|
| Head & neck | 4 | 2 | ×0.1 | 0.8 |
| Upper limbs | 8 | 3 | ×0.2 | 4.8 |
| Trunk | 6 | 2 | ×0.3 | 3.6 |
| Lower limbs | 2 | 1 | ×0.4 | 0.8 |
EASI = 0.8 + 4.8 + 3.6 + 0.8 = 10.0 → Moderate (Leshem 2015 band 7.1–21.0).
Formula reference
| Region | Multiplier (8+) | Multiplier (<8) |
|---|---|---|
| Head & neck | 0.1 | 0.2 |
| Upper limbs | 0.2 | 0.2 |
| Trunk | 0.3 | 0.3 |
| Lower limbs | 0.4 | 0.3 |
Area score
| % involved | 0 | 1–9 | 10–29 | 30–49 | 50–69 | 70–89 | 90–100 |
|---|---|---|---|---|---|---|---|
| Area score | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
Leshem 2015 severity bands
| EASI | Band |
|---|---|
| 0 | Clear |
| 0.1–1.0 | Almost clear |
| 1.1–7.0 | Mild |
| 7.1–21.0 | Moderate |
| 21.1–50.0 | Severe |
| 50.1–72.0 | Very severe |
Sources: Hanifin et al., Exp Dermatol 2001; Leshem et al., Br J Dermatol 2015; HOME EASI guidance (homeforeczema.org). Full citations in the tool's SOURCES file.
Related calculators: APGAR score calculator · Adjusted age calculator
Frequently asked questions
What is the EASI score?
The EASI (Eczema Area and Severity Index) is a validated investigator-assessed instrument that measures the severity of atopic dermatitis (eczema). It was developed by Hanifin et al. (Experimental Dermatology, 2001) and is one of the core outcome instruments recommended by the HOME (Harmonising Outcome Measures for Eczema) initiative for all atopic dermatitis clinical trials. The score ranges from 0 (no disease) to 72 (maximal disease).
How is the EASI score calculated?
The body is divided into four regions: head & neck, upper limbs, trunk, and lower limbs. For each region you grade four clinical signs — erythema (redness), edema/papulation (swelling), excoriation (scratch marks), and lichenification (skin thickening) — on a scale of 0 (none) to 3 (severe), and you estimate the percentage of the region involved, converted to an area score of 0–6 (0: none, 1: 1–9%, 2: 10–29%, 3: 30–49%, 4: 50–69%, 5: 70–89%, 6: 90–100%). The region score is (erythema + edema + excoriation + lichenification) × area score × region multiplier (0.1 head/neck, 0.2 upper limbs, 0.3 trunk, 0.4 lower limbs for patients aged 8+). The four region scores are summed for the final EASI (0–72).
What are the EASI severity bands?
The widely used interpretability bands come from Leshem et al. (British Journal of Dermatology, 2015): 0 = Clear; 0.1–1.0 = Almost clear; 1.1–7.0 = Mild; 7.1–21.0 = Moderate; 21.1–50.0 = Severe; 50.1–72.0 = Very severe.
Can you show a worked EASI example?
Sure — adult patient, age 8+. Head & neck: signs (2,1,1,0) sum to 4, 20% area → area score 2, ×0.1 = 0.8. Upper limbs: signs (3,2,2,1) sum to 8, 40% area → area score 3, ×0.2 = 4.8. Trunk: signs (2,2,1,1) sum to 6, 20% area → area score 2, ×0.3 = 3.6. Lower limbs: signs (1,1,0,0) sum to 2, 5% area → area score 1, ×0.4 = 0.8. Total EASI = 0.8 + 4.8 + 3.6 + 0.8 = 10.0, which falls in the Moderate band (7.1–21.0).
Do children under 8 use different multipliers?
Yes. Because body proportions differ in young children, the under-8 EASI form uses region multipliers of 0.2 for head/neck, 0.2 for upper limbs, 0.3 for trunk, and 0.3 for lower limbs (instead of 0.1 / 0.2 / 0.3 / 0.4 for age 8+). This calculator includes an age-group toggle so you can select the correct multiplier set.
Can I use half points like 1.5 or 2.5 for sign severity?
Yes. The official EASI case report form permits half points 1.5 and 2.5 when grading a sign. However, 0.5 is not permitted — if a sign is present at all, it should be scored at least 1 (mild). The severity grade should represent the average intensity across the involved area of that region.
Which skin areas count as involved in EASI?
Include only inflamed areas in your assessment. Do not include xerosis (dryness), ichthyosis, keratosis pilaris, urticaria, infection (unless there is underlying eczema), or post-inflammatory pigmentation changes. The area percentage is estimated per body region, and each region can potentially reach 100% involvement.
Can I use the EASI calculator to diagnose my eczema?
No. EASI is a severity index designed for clinical and research use by trained assessors — it is not a diagnosis. Only a dermatologist or qualified clinician can diagnose eczema and decide on treatment. If you are concerned about your skin, please see a dermatologist rather than relying on a self-computed score.