For some people, foot pain is the worst part of psoriatic arthritis (PsA) — and that makes the right foot care essential.
"Psoriatic arthritis can affect the joints of the feet and ankles, and it can also affect the structures that support those joints," said M. Elaine Husni, MD, MPH, vice chair of rheumatology and director of the Arthritis & Musculoskeletal Center at the Cleveland Clinic in Ohio and an assistant professor at the Cleveland Clinic Lerner College of Medicine at Case Western Reserve University. When psoriatic arthritis and inflammation affect tendons that support joints, the condition is called enthesopathy. Pain and stiffness caused by psoriatic arthritis enthesopathy may start before actual joints are affected.
Inflammation Symptoms in the Feet
"Foot and ankle symptoms from psoriatic arthritis can be confused with injuries," said Dr. Husni. "But in most cases psoriasis skin symptoms start before arthritis symptoms, which makes the diagnosis easier."
Conversely, it can be harder for you to get the right diagnosis of psoriatic arthritis of the feet or ankles if you don't have skin psoriasis. About 15 percent of people with psoriasis develop psoriatic arthritis, and in some cases psoriatic arthritis comes before any skin symptoms. In rare cases, someone can have psoriatic arthritis without ever having psoriasis.
Foot involvement with psoriatic arthritis may include:
Plantar fasciitis. "This causes pain in the sole of the foot from inflammation of the supporting tissue," said Husni. Plantar fasciitis with a bone spur on the heel is a common cause of psoriatic arthritis foot pain. Pain may be felt on the bottom of the foot near the heel, especially when you take your first steps in the morning.
Achilles tendinitis. "Enthesitis is inflammation at an area where tendons attach to bones," Husni said. "The Achilles tendon attachment is a common site causing heel pain." Achilles tendonitis causes pain in the back of the lower leg, near the heel. The pain gets worse with exercise that involves ankle movement, and there may also be tenderness and swelling.
Dactylitis. "Dactylitis is swelling of the tendon that runs along the length of a toe or finger," Husni said. "It can cause swelling that makes toes or fingers look like sausages." Dactylitis affects about a third of those who have psoriatic arthritis, and toes are more commonly affected than fingers.
Nail and skin change. "People with psoriasis and psoriatic arthritis may have skin psoriasis called pustular psoriasis on the soles of their feet. "Toenails can become pitted or start to lift away from the nail bed," said Husni.
Foot deformities. Long-term foot changes can occur if psoriatic arthritis goes untreated. These include clawed toes, upward bending of the big toe, flat foot, rolling of the ankle, and calluses or ulcers on the soles.
How to Take Care of Your Feet With PsA
"Treatment can range from occasional anti-inflammatory pain medications like Advil or Motrin to more powerful drugs like DMARDs, which stands for disease-modifying antirheumatic drugs, and biologics," said Husni. Self-management should also be part of your foot care for psoriatic arthritis.
Here are 10 foot care tips to master:
- Avoid weight-bearing exercises that make your feet ache. "When your feet start to hurt, you need to get off them," Husni said.
- Get help from a physiotherapist or podiatrist along with your psoriasis doctors for special foot care and to learn more about psoriatic arthritis and shoes.
- Have your feet measured, for both length and width. This will help you choose the right shoes.
- Make sure your shoes are wide enough and long enough to allow room for some swelling.
- Make sure your shoes have good arch and heel support. "You can try over-the-counter insoles from the pharmacy, or you can have orthotics fitted and made specially," said Husni.
- If your ankles are weak or painful, get shoes with high ankle support or consider ankle splints.
- Stretching exercises are important for psoriatic arthritis. Try lying flat with your feet extended off the end of the bed. With your legs held still, move your feet up and down and then around in circles; repeat for a total of 10 times. Do your foot-stretching exercises at least once every day.
- If you're going through a painful foot flare, try using a cane or crutches until inflammation subsides.
- A good foot massage can improve circulation and help relieve foot pain.
- "Foot soaks can help relieve pain," Husni said. "You can do a hot soak or a cold soak — whatever feels better."
Psoriatic arthritis often involves the feet and ankles, causing both pain and swelling. Treatment works, but foot deformities can develop if treatment is delayed. If you've been diagnosed with psoriasis, always let you doctor know about any foot or ankle symptoms.
And remember that psoriatic arthritis sometimes occurs without any skin symptoms, so don't ignore your feet. They have a big job to do, and they need all the support they can get.