CASPAR criteria and psoriatic arthritis

The name refers to Classification Criteria for Psoriatic Arthritis. Clinicians and specialist teams may use the framework to identify a consistent pattern, but it is not a home checklist and does not replace clinical diagnosis. A person can need rheumatology assessment even when every classification feature is not present.

The starting point is evidence of inflammatory disease affecting joints, the spine or the places where tendons and ligaments attach to bone. The clinician then considers current or previous psoriasis, a family history of psoriasis, typical nail changes, swelling of an entire finger or toe, particular imaging changes and a blood test used to help distinguish other inflammatory arthritis patterns.

No single skin patch, painful joint or blood result establishes psoriatic arthritis. Psoriatic arthritis commonly presents with joint pain, swelling and stiffness, but these symptoms also occur in other conditions. Skin disease may be subtle, hidden in the scalp or skin folds, or may have appeared before or after joint symptoms.

Record which joints hurt or swell, whether stiffness is worse after rest, and whether a whole finger or toe has become puffy. Mention heel or other tendon-attachment pain, back stiffness, nail pitting or separation, and any psoriasis in you or close relatives. Photos of intermittent swelling or rashes can help when those signs are absent on appointment day.

A clinician may examine the skin, nails, joints, spine and tendon attachments, then decide whether blood tests or imaging would clarify the pattern. If psoriatic arthritis is diagnosed, management may combine medication to control inflammation with pacing, movement and physiotherapy chosen for the joints and tissues involved.

Arrange a medical review when persistent joint swelling, repeated whole-digit swelling, or morning stiffness interferes with movement or daily tasks. Earlier assessment is especially useful when these problems occur with psoriasis or nail changes, because uncontrolled inflammation can affect joint function.

Seek same-day care for a suddenly hot, red and very painful joint, particularly with fever or feeling unwell, because joint infection and other urgent causes must be considered. Eye pain, marked redness, light sensitivity or blurred vision also needs urgent assessment. New severe weakness, loss of bladder or bowel control, or numbness around the groin requires emergency care.

Ask what findings show inflammation rather than mechanical pain, which alternative diagnoses are being considered, and whether a rheumatology referral is appropriate. If treatment is proposed, ask what it aims to control, how response and side effects will be monitored, and which exercises or activity changes protect function without aggravating an inflamed joint.