Skip to main content
Back to Dermatology Tests

Could I Have Psoriatic Arthritis?

Take the PEST (Psoriasis Epidemiology Screening Tool), used by dermatologists to screen for psoriatic arthritis. 5 questions about joint pain, swelling, nail changes, heel pain, and digit swelling. Scores of 3+ suggest further evaluation. Instant results.

5 questions~2 minutes

Before You Start

  • This is a screening tool, not a diagnostic test
  • All answers are processed in your browser only
  • No data is stored or sent to any server
  • Results can be copied to share with your clinician

What Is the PEST Screening?

The Psoriasis Epidemiology Screening Tool (PEST) is a validated 5-question screening questionnaire designed to identify psoriatic arthritis in people with psoriasis. Up to 30% of people with psoriasis develop psoriatic arthritis, but it is often diagnosed late — on average 2 years after symptom onset. Early detection matters because prompt treatment can prevent permanent joint damage.

Warning Signs of Psoriatic Arthritis

Psoriatic arthritis can develop at any time, even years after psoriasis first appears. Key warning signs include joint pain or stiffness (especially in the morning or after rest), swollen fingers or toes (sometimes called "sausage digits"), heel or foot pain, lower back stiffness, and nail changes like pitting or separation from the nail bed. If you have psoriasis and experience any of these, this screening can help determine whether further investigation is needed.

How the PEST Works

The PEST consists of 5 simple yes/no questions about joint symptoms. It also includes a body diagram where you can indicate which joints are affected. A score of 3 or more out of 5 suggests possible psoriatic arthritis that warrants referral to a rheumatologist. The PEST has been validated in multiple studies and is recommended by NICE guidelines for screening psoriasis patients.

What to Do Next

If your PEST score suggests possible psoriatic arthritis, the next step is to discuss your results with your GP or dermatologist, who can arrange a referral to a rheumatologist. Early treatment with disease-modifying therapies can prevent joint damage and significantly improve quality of life. Do not ignore joint symptoms — psoriatic arthritis is highly treatable when caught early.