Psoriatic arthritis (PsA) is an autoimmune disease closely linked to psoriasis, a condition that causes red, scaly, and inflamed skin patches. In PsA, the immune system mistakenly attacks healthy tissues, leading to joint pain, stiffness, and swelling — particularly in the fingers, toes, ankles, knees, wrists, and lower back.

This chronic condition can appear differently from person to person. For some, symptoms may come and go in flares, while for others, the disease progresses steadily and affects multiple joints over time.

What Are Common Symptoms?

stiffness, swelling, and pain
The most recognizable signs of PsA are stiff, swollen, and painful joints. The severity and number of joints affected vary among individuals.

PsA is often asymmetrical, meaning only one side of the body may be affected. For example, a person might have joint pain in the right hand but not in the left. In some cases, neighboring joints may even show very different levels of damage.

As rheumatologist Dr. Ted Mikuls explains, “You can have severely involved joints with nearby joints showing almost complete preservation. It can be very spotty.”

This uneven pattern is a key visual clue for diagnosing PsA.

Fingers Affected by PsA

nail and knuckle changes
One of the most distinctive features of PsA is how it affects the fingers and nails. Sometimes, inflammation targets the last joint near the fingertip (the distal joint) while sparing other joints.

Common signs include:

  • Swelling around one or more finger joints

  • Redness and tenderness near the nails

  • Nail pitting, ridging, discoloration, or thickening

  • Nail separation from the nail bed

These nail and fingertip changes are often visible indicators of psoriatic arthritis and can appear even before joint pain begins.

Deformity and Swelling of Fingers and Toes

dactylitis or “sausage digits”
Another hallmark symptom of PsA is dactylitis, a condition where an entire finger or toe becomes swollen, red, and painful — resembling a sausage. This occurs when inflammation spreads throughout the joints and soft tissues.

Dactylitis may affect one or several fingers or toes and can cause noticeable deformity over time if left untreated. The swelling can make everyday tasks like gripping, typing, or walking uncomfortable.

Other Symptoms

beyond the joints
Psoriatic arthritis doesn’t only affect the joints. It can also impact tendons, ligaments, and even organs.

tendon and ligament pain: Inflammation can develop where tendons attach to bones — such as in the heels, feet, or elbows — leading to stiffness and discomfort.

fatigue: Chronic inflammation can cause deep, lingering fatigue that affects focus and daily activities.

eye inflammation (uveitis): PsA can cause uveitis, an inflammation of the middle layer of the eye (uvea). Symptoms include eye pain, redness, blurred vision, and sensitivity to light. Without prompt treatment, uveitis can lead to permanent vision loss.

Because PsA is systemic, managing inflammation through medication and lifestyle changes is critical to prevent complications in both the joints and other organs.

A Quick Review

Psoriatic arthritis is an autoimmune condition that affects the skin, joints, and nails. It can cause swelling, stiffness, deformities, and fatigue, with symptoms ranging from mild discomfort to severe joint damage.

Recognizing visual signs such as nail changes, dactylitis, and asymmetrical swelling can help in early detection and treatment. Timely management is essential to maintain joint mobility and prevent complications like vision problems or chronic pain.