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Patient-oriented PASI score

Dr Sam MacGill, Medical Student, University of Otago, Wellington, New Zealand. DermNet NZ Editor in Chief: Adjunct A/Prof. Amanda Oakley, Dermatologist, Hamilton,  New Zealand. May 2020.

Patient-oriented PASI score — codes and concepts

Go to the PO-PASI tool.

What is chronic plaque psoriasis?

Psoriasis is a skin disorder characterised by scaly red skin. Chronic plaque psoriasis is the most common form of psoriasis, in which there are persistent, symmetrical, erythematous, scaly plaques often located on scalp, trunk, and limbs. There can be few or many plaques, with varying redness, thickness and scale.

Chronic plaque psoriasis of varying severity

What is a PASI score?

PASI is an acronym for Psoriasis Area and Severity Index. The method has been widely adopted to provide health professionals with an approximate numerical way of describing a patient's chronic plaque psoriasis. The PASI score has been used in clinical trials of medications and to determine the eligibility for funded medications and the efficacy of treatment.

  • A PASI score of < 5 indicates mild chronic plaque psoriasis
  • A score of 5–10 represents moderate chronic plaque psoriasis
  • A score of > 10 describes severe chronic plaque psoriasis

The maximum PASI score is 72.

What is a patient-oriented PASI score?

The patient-oriented psoriasis area and severity index tool (PO-PASI) has been devised by DermNet NZ for patients with chronic plaque psoriasis to help them estimate their own PASI score

How is the PO-PASI determined?

The PO-PASI score is automatically calculated.

The participant first selects the diagram or photograph that best resembles the area of skin affected by psoriasis in each of four body parts:

  • Head and neck
  • Trunk
  • Upper limb
  • Lower limb.

The participant also selects the photographs that most resemble the redness, thickness, and scaling of psoriasis plaques in each of the four body parts. The tool then creates a certificate which includes the total score.

How is the PO-PASI useful?

The PO-PASI is useful for remote assessment of a patient by a dermatologist or other health professional to determine the best treatment and whether the treatment has proved effective. The patient can also maintain their own clinical record.

Has the PO-PASI been validated?

As the design of the PO-PASI tool was completed during the COVID-19 lockdown, we have not yet had the opportunity to validate its accuracy. During the lockdown in New Zealand, patients with psoriasis are assessed by teledermatology (phone calls, video consultations, and electronic referral systems).

The planned validation of PO-PASI will involve the determination of the PASI score by a health professional examining the patient in person. The PASI score will be compared to patient's own PO-PASI as part of an Ethics committee-approved research study, which the Department of Dermatology, Waikato District Health Board plans to conduct later in 2020 and 2021.

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