What is Distal Interphalangeal Predominant Psoriatic Arthritis?

Distal interphalangeal predominant (DIP) psoriatic arthritis (PsA) primarily affects the small joints in the fingers and toes closest to the nails. DIP PsA accounts for less than 10% of PsA cases, and while rare, it will get worse without proper and successful treatment.

Symptoms

Psoriatic arthritis is known for starting at the distal interphalangeal (DIP) joints, which are the joints closest to the fingernails and toenails. Stiff and inflamed fingers will make it harder to perform the simplest tasks, such as zipping a jacket or opening a jar. Stiff and swollen toes make walking and standing for long periods painful.

Swelling associated with DIP PsA usually affects the entire finger or toe. It is asymmetric, meaning it affects only one side of the body. That means that if all the joints in one hand are affected, the other hand may not be affected at all, or four or less digits are involved. However, research shows PsA can also be symmetrical, involving the joints on both sides of the body. Moreover, DIP PsA occurs more frequently in the toes.

DIP psoriatic arthritis also causes enthesitis, inflammation at the places where ligaments and tendons meet at the bones. The type of swelling and inflammation can erode the joints and lead to deformity and loss of function.

Reducing Pain and Disability

Minor pain and stiffness can be managed with non-steroidal anti-inflammatory drugs (NSAIDs). Corticosteroid injections can reduce inflammation and treat pain from DIP PsA. 

For people who have moderate or severe disease symptoms, targeted treatments, including disease-modifying anti-rheumatic drugs (DMARDs), and tumor necrosis factor (TNF) inhibitors can reduce symptoms and prevent disease progression. Physical and occupational therapy can protect joints and help to maintain function. 

Surgery is considered as a last option to alleviate severe pain and repair joint damage. However, joint damage from DIP PsA might recur, especially in the fingers.

Coping

DIP psoriatic arthritis can be painful and affect life quality. The following are also ways to help with coping:

• Cold therapy: An ice pack or a bag of frozen vegetables can help alleviate swelling in the hands and fingers. It's a good idea to alternate between cold and heat or off and on every 10 minutes. A frozen water bottle rolled under the foot can reduce swelling and massage the foot, heel, and toes.
• Nail and cuticle protection and maintenance: Because DIP PsA affects the nails, they should be trimmed, filed and moisturized regularly. If nails are professionally done, cuticles should not be treated to avoid tiny tears. And skin injuries—no matter how small—can trigger PsA symptoms and increase the chance of infection in people taking immune-suppressant drugs.
• Soaking hands and feet: A warm hand or foot soak can alleviate pain and swelling in hands and feet. Soaks should be short to avoid drying out skin and making skin symptoms worse. It's also a good idea to moisturize skin after soaking.
• Keep feet dry: To avoid sweating in the feet, try moisture-wicking socks. These socks—made from nylon, polyester or wool—pull sweat from skin to the fabric and then evaporate wetness. If shoes are wet, take them off as soon as possible and allow them to completely dry out before putting back on.
• Pick the right shoes: Wide-width and open-toe shoes are generally recommended for people with different types of arthritis. Pointy toe shoes and high heels should be avoided because they cramp feet and push toes forward.

Summary 

Distal interphalangeal predominant psoriatic arthritis can cause pain and disability and affect daily routines and quality of life. There are many ways to treat the condition and ways to cope with pain and swelling. And while there is no cure for DIP PsA, treatment can help the condition to become more manageable and prevent joint deformity and disability.