What Is the Psoriasis Symptom Inventory?

The psoriasis symptom inventory (PSI) assesses your psoriasis. It scores the severity of 8 symptoms to give an overall score of disease severity. It is easier to use than other measures. You can even use it to score yourself. It is also used in clinical trials to see how well treatments work.

The PSI measures patient-reported outcomes (PROs). This means that it uses only your report of your own symptoms. It does not include any input from doctors.

What are patient-reported outcomes?

The main goals of psoriasis treatment are to control symptoms and to improve quality of life. In order to do this, it is important to take into account patients' takes on their own symptoms. These may be used in clinical trials to evaluate how well a treatment works.¹

PROs are reports of symptoms and health conditions directly from the person with the condition. Doctors’ assessments and clinical measures are not included in PROs.²

The PSI is a new measure of PROs that assesses the severity of psoriasis symptoms. Before the PSI, there were other measures. But these were not used as often because they were not specific or simple enough. Studies have shown that the PSI is reliable and accurate.³

What are the questions on the psoriasis symptom inventory?

The PSI assesses the severity of 8 psoriasis symptoms. The questions address:⁴

• Itching
• Redness
• Scaling
• Burning
• Stinging
• Cracking
• Flaking
• Pain

Each question asks how severe each symptom is on a scale of 0-4:¹

• 0: Not present
• 1: Mild
• 2: Moderate
• 3: Severe
• 4: Very severe

Individual scores are added for a total score, which can range from 0 to 32. A higher score means that someone reports having more severe symptoms.

How is the psoriasis symptom inventory used?

The PSI has been used as either a 24-hour recall or a 7-day recall. The 24-hour recall version can show day-to-day fluctuations. The 7-day recall version can show how symptoms change over 1-week periods. Both versions usually show similar and accurate results.^1,4

The PSI can be used to see how well a certain therapy is working. Doctors can evaluate how your PSI changes over time. This can tell them whether your symptoms are getting worse or improving. And it can help them make further decisions about your treatment.

You can even use the PSI to track your own symptoms. Ask your doctor how to calculate your own PSI. This way you can record changes yourself.

The PSI is also used in clinical trials to evaluate treatments. Improved PSI shows that a treatment may be useful for people with psoriasis. For example, the PSI was used in clinical trials for brodalumab. After 3 months of taking brodalumab, people with psoriasis had improved PSI responses.^1,5,6