electronic Psoriasis Area Severity Index


Psoriasis assessment made easy and quick

What is the ePASI

ePASI is a calculator tool for dermatologists and physicians, based on the Psorisis Area Severity Index (PASI).


The PASI score is used in experimental dermatology to evaluate the efficacy and safety of drugs used for the treatment of psoriasis. ePASI is available as a mobile application for Android and iOS devices, as well as a web-based online calculator.

How to use the ePASI

ePASI assesses four body regions: i) the head and neck, ii) the hands and arms, iii) the chest, abdomen and back (trunk) and iv) the buttocks, thighs and legs. Each region is given a score based on the extent and severity of the psoriasis. The area extensity score can range from 0 (no psoriasis) to 6 (all of the skin affected). The severity score, based on redness, thickness and scaling, is rated from zero (none) to 4 (very severe). The final score falls between the range of 0 (no psoriasis) to 72 (maximum psoriasis).

Treatment should not only take itch into consideration but also scratching-induced skin lesions and accompanying disorders such as anxiety, depression and insomnia.  


The ePASI score

For each subarea a score is determined:

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Score - Head:


Scores for redness, scaling and thickening on the head (sum between 0 and 16) multiplied by the body surface (head 0-6), multiplied by 0.1.

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Score - Trunk:


Scores for redness, scaling and thickening on the trunk (sum between 0 and 16), multiplied by the body surface of the trunk (between 0 and 6), multiplied by 0.3.

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Score - Arms:


Scores for redness, scaling and thickening on arms (sum between 0 and 16) multiplied by the body surface (arms 0-6) multiplied by 0.2.

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Score - Legs:


Scores for itching, redness, scaling and thickening on legs (sum between 0 and 16) multiplied by the body surface of legs (between 0-6) multiplied by 0.4.

The addition of the 4 partial scores results in a total score (between 0 and 72) = PASI


1) Severity of Psoriatic lesions

Please circle a number for each of the following: erythema (redness), induration (thickness) and scaling. The severity score is rated from zero (none) to 4 (very severe).


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2) Affected body surface

Please note the affected area for the respective body region in line 6. Circle the respective numbers before the percentages.
Multiply result from No.4 with the number you chose in No.6. 


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Multiply the result you got in line 7 with the number in line 8. Each body region has a different number corresponding to that area. For Head multiply the result in line 7 with 0.1. For Trunk: x 0.3; For Arms: x 0.2; For Legs: x 0.4.


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Sum up all the numbers in line 9 to get the final PASI score.


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Want to know more?


Download the full PDF guide and access all text and visual tips for your PASI
calculations everywhere.




Want to know more?


Download the full PDF guide and access all text and visual tips for your PASI
calculations everywhere.



Following you can find the versions of the ePASI


Plate XXIII, Psoriasis. Crocker 1896
Credit: Wellcome Library, London

About Psoriasis


Psoriasis is a long-lasting autoimmune disease known by its abnormal patches of skin (red, itchy and even scaly).


“Psoriasis is a chronic inflammatory disease, with an incidence in Western industrialized countries of 1.5 % to 3 %. It represents a great burden to the patient due to marked loss of quality of life, therapy-refractory course and frequent side effects of therapy.”


Prof. Dr. med. Matthias Augustin



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ePASI design comprises clear, clickable images and their descriptions, making completion of the questionnaire understandable for both doctors and patients.

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Save time with our online tool. Fill out the questionnaire and get your results straight away, without doing any calculations.

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PASI is currently the most widely used tool for measuring the severity of pruritus.

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PASI is a standard procedure for anyone, so choose your preferred language to fill the information in and forget about language barriers.

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Your Psoriasis Index is always a couple of touches or clicks away at ePASI, available on desktop, tablet, phone and other devices.

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Put an end to wasting paper and store all your patient data in an online platform. Results can be shared via email.

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