How Psoriatic Arthritis Affects Feet

 How Psoriatic Arthritis Affects Feet

Psoriatic arthritis (PsA) can have serious effects on the feet from heels to toes. Sometimes the damage is debilitating and it may become permanent. Fortunately, flares in symptoms can be managed and relieved, and there also are strategies for preventing problems. Overview

Psoriatic arthritis is a type of inflammatory arthritis that causes pain, swelling, and inflammation of the joints. PsA is an autoimmune disease, which means it is the result of your immune system malfunctioning and attacking healthy tissues.

With PsA, the immune system attacks the joints and the skin. PsA affects up to 85% of people with a history of psoriasis, although you do not have to have psoriasis to have PsA.1

PsA targets joints and skin throughout your body, including the hands and feet. When it affects the feet, it might cause substantial pain and swelling, starting at the heels and going as far as the ends of your toes.

PsA foot involvement can lead to disability. Unfortunately, this a complication of PsA that isn't addressed often enough. And the lack of attention towards it means a severe and negative impact on the quality of life for those affected.

Fortunately, treatment for PsA and specific foot symptoms can help you to feel better, manage pain, slow down the disease’s progression, reduce periods of high disease activity (flare-ups), and prevent joint damage that would impact life quality. Keep reading to find out how PsA might affect your feet and what you can do about it.
Heels and Ankles

Enthesitis is a symptom unique to PsA and other types of spondylarthritis —an umbrella term for types of arthritis that affect the spine and, sometimes, the joints in the arms and legs. Because of this uniqueness, doctors will look for enthesitis to distinguish PsA from other types of inflammatory arthritis like rheumatoid arthritis (RA).2

Enthesitis means there is pain and inflammation in the enthesis, the connective tissues between the tendons or ligaments, and the bones.

Inflammation of the enthesis can affect the heels and the ankles. In the heels, this inflammation occurs at the Achilles tendon—the place in the back of the foot where there is a tough band of tissues. That band of tissue connects your heel bone to your calf muscle.

At the ankles, PsA causes inflammation in the area where the tendons or ligaments meet bone to facilitate joint movement.
Enthesitis of Achilles Tendon

One study reported in 2017 in the journal Arthritis & Care, found up to 35% of people with PA develop enthesitis, with the Achilles tendon being the most commonly affected area.3 Inflammation at the Achilles tendon will cause pain and swelling at the heel, making walking, running, or climbing steps harder.

As the enthesitis worsens, your tendons and ligaments will become thicker or harder, and more swollen, which adds more pain and difficulty when you step down on your foot. Your doctor can request an ultrasound or MRI to determine the extent of the enthesitis.

There is no specific treatment for enthesitis, but treatment is generally aimed at the condition causing it. With PsA, that entails a mix of medication, rest, and physical therapy. Non-steroidal anti-inflammatory drugs (NSAIDs), including ibuprofen and naproxen, can help you to manage pain and reduce inflammation.

Your doctor might also prescribe a disease-modifying anti-rheumatic drug (DMARD) or a biologic drug to slow down the effects of the disease. Your doctor might also recommend corticosteroid therapy to treat areas that are particularly stiff and hard.4

Treatment with TNF inhibitors (biologics) is recommended for people with enthesitis connected to PsA when they do not respond to NSAID therapies.4

Research shows that TNF therapies, like adalimumab, etanercept, infliximab, and golimumab, are quite effective for treating enthesitis. Adalimumab and etanercept both have been reported to effective for treating heel enthesitis, with continuing improvements lasting over six months.4

When enthesitis affects the Achilles tendon, it makes it harder for you to extend your ankle, which further adds to difficulties with walking. Swelling from the Achilles tendon will also move into the back of the ankle, leading to ankle pain and problems with movement of the ankle.

In addition to enthesitis swelling, people with PsA will also have joint pain and swelling in their ankles and feet. Pain and stiffness might be worse in the morning upon waking or after sitting for a long period.

Joint pain in the ankles is treated similarly to other types of inflammatory arthritis. This includes medication to relieve pain and prevent long-term damage. Treatment might also include lifestyle changes, bracing of the affected ankle, and anti-inflammatory medicines to ease inflammation, pain, stiffness, and swelling.

The midfoot is the middle part of the foot, containing a cluster of small bones that form an arch at the top of your foot. PsA affects the midfoot by causing generalized swelling throughout the midfoot, tenosynovitis, plantar fasciitis, and palmoplantar pustular disease.

Tenosynovitis, or inflammation of tendon sheath, commonly affects the feet and ankles in people with PsA. It leads to joint pain, swelling, and stiffness. While rarely discussed in the research, tenosynovitis of the toe flexor tendons can occur with PsA.

The flexor tendons help you to bend your toes and fingers. The flexor tendons that help you to bend your toes actually originate from two muscles of the lower leg.5 They run down to the inside of the ankle and under the foot.

A 2011 review in the Journal of Immunology Research looked at the results of one study that found tenosynovitis in the flexor tendons of the fingers and toes of people with PsA.6 In that study, researchers found evidence in ultrasound imaging showing thickness and swelling of the flexor tendons, findings specific to PsA.
Plantar Fasciitis

Both plantar fasciitis and palmoplantar psoriasis can affect the bottom of the foot at the sole and the plantar fascia. The plantar fascia is located at the bottom of the foot. It is the dense band of connective tissue that connects the heel to the front of the foot.

Plantar fasciitis causes inflammation in the plantar fascia. Some evidence suggests people with PsA might have a higher risk for plantar fasciitis.7 This is because enthesitis from PsA can occur anywhere in the body and commonly at the Achillies tendon which attaches to the plantar fascia.

Plantar fasciitis can cause dull or sharp pain when you step down on your foot. Other symptoms include swelling and stiffness at the heel. Plantar fascia pain is managed with ice, rest, exercises, splinting and bracing, and taping (to relieve pressure off the plantar fascia).8
Palmoplantar Psoriasis

People with PsA who have severe psoriasis are more likely to have a condition called palmoplantar psoriasis (PPP).9 PPP is also called pustular psoriasis.

PPP causes blister-like sores on the soles of the feet, cracked skin, and red, scaly patches.10 These symptoms make walking painful and uncomfortable. PPP can also affect the palms of the hands.

Some researchers have suggested that PPP is a variant of psoriasis, while others believe it is a separate condition.10 Regardless of how it is categorized, symptoms are caused by the immune system attacking healthy skin cells.

There is no cure for PPP, but it is treatable. PPP is treated with topical steroids and photochemotherapy, an ultraviolet radiation treatment.10 Other treatments include immunosuppressive drugs like cyclosporine.

In some instances, even with ongoing treatment, blisters and sores will keep coming back.9 But it is possible for skin symptoms to go away and not return.
PsA and the Toes

PsA can cause inflammation in the toes. Similar to the way PsA affects the fingers, it can cause swelling of one or more toes and changes to the toenails.

Dactylitis, sometimes called sausage toes, is a condition that causes swelling of entire digits (toes and fingers). It is often called sausage toes because the swollen toes resemble little sausages. One 2018 review of studies in the journal Seminars in Arthritis and Rheumatism finds up to 49% of people with PsA will have dactylitis.11

Dactylitis occurs when the small joints of the toe, as well as the entheses of the tendons, become inflamed. It is a very painful symptom of PsA that will affect your ability to walk, step down on affected toes, and wear socks or shoes comfortably.

Gout—another type of inflammatory arthritis—can also cause swelling and pain in your toes. Studies show people with PsA and/or psoriasis have a greater risk of developing gout.12

Gout is characterized by sudden, severe attacks of pain, swelling, tenderness, and redness of the joints, usually at the top of the toe. Gout symptoms will come and go, and there are ways to manage symptoms and prevent flare-ups. You can have symptoms of both gout and dactylitis occurring at the same time.13
Metatarsophalangeal Joint Pain

The metatarsophalangeal (MTP) joints are located between your toes and the bones in the main part of the foot. PsA can cause pain in the areas of the toes where the MTP joints are located.14 MTP joint pain is caused by PsA inflammation and can lead to joint damage throughout the foot.

Synovitis or inflammation of the lining of the joints (the synovium) can affect the fingers and toes. Long term synovitis in PsA might lead to bone destruction. This is especially common where inflammation starts at the entheses and then triggers secondary joint synovitis.11
Distal Interphalangeal Predominant PsA

Distal interphalangeal predominant (DIP) PsA primarily affects the small joints of the fingers and toes that are closest to the finger and toenails. It affects about 10% of people with PsA.6

DIP PsA causes stiffness and pain in the toes, especially in the morning. Stiff and painful toes make to harder to walk and stand for long periods. DIP PsA may also cause nail changes, including detachment, discoloration, crumbling, and pitting (small indents).
Arthritis Mutilans

Arthritis mutilans is a severe and rare form of PsA. It affects less than 5% of people with PsA.15 It causes severe inflammation that eventually causes damage to the feet and toes, shortening of toes, deformity, and loss of use. Early and aggressive treatment can reduce this complication and should start as soon as a person is diagnosed with AM.
What You Need to Know About Arthritis Mutilans

Up to 80% of people with PsA will have nail involvement, according to a 2017 report in the journal Reumatologia.16 Nail symptoms of PsA are visible and include pitting, white spots, discoloration, onycholysis (where nails separate from the nail bed, and onychorrhexis (brittle nails).

Additional nail symptoms may include hyperkeratosis (buildup of grey keratin cells under the nails) and splinter hemorrhages (tiny blood spots under nails from damaged capillaries in the nail beds). Fungal nail infections are also common in people with PsA.16
Nail Problems Associated with Psoriasis

According to the Psoriasis Foundation, foot and hand involvement in PsA has not always been recognized or addressed.15 But newer research has given doctors more information on how to prevent this type of PsA involvement, as well as how to treat it.

In general, treating PsA with DMARDs and/or biologics can help to relieve and improve symptoms of dactylitis and enthesitis and reduce or prevent inflammation responsible for other foot and toe symptoms.15 Treatment that specifically focuses on PsA of the feet and toes will depend on severe your symptoms are.

Treatment might include steroid injections directly into a joint to manage inflammation in that joint or beneath a toenail to control nail symptoms.17

And because foot and toe involvement might indicate more severe or aggressive disease, your doctor will likely revisit your PsA treatment plan to determine if additional medications or increased medication doses might help to get the disease under control. Or they may want to completely remove a medication, or more than one, from your treatment plan and add others.

Your doctor might also recommend some things you can do at home to manage symptoms. Things you can do to ease inflammation and pain at home include:

Using cold packs to numb the pain and bring down swelling
Keeping your nails short to reduce nailbed separation
Wearing shoes that offer support and give your feet room to breathe
Elevating the feet to get pressure off and ease swelling
Soaking your feet in warm water. Ask your doctor if it is safe for you to use Epsom salt.
Taking anti-inflammatory pain relievers to bring down swelling and ease pain
Prevention of Foot and Toe Involvement

PSA is a condition that gets worse with time. While there is no cure for the condition, there is still a lot you can do to manage symptoms, control inflammation, protect your joints, and reduce the effects it can have on your feet and toes.

To keep your feet healthy, make sure you stick to your treatment plan. Your doctor might prescribe medications to relieve pain and inflammation, to slow down the disease, and to act on the immune system to manage symptoms and prevent disease progression but these can’t help if you don’t make good use of them.

Your doctor may also recommend that you maintain a healthy weight to reduce stress to the joints of your feet, relieve foot pain, and improve your gait (the way you walk).

Exercise is important to keep joints flexible and boost your energy. Try activities that put the least amount of stress on the joints, such as swimming and walking. Focus on stretching the joints, ligaments, and tendons that are the source of foot pain. Ask your treating doctor or physical therapist about exercises that are safe for your feet.
A Word From Verywell

If PsA has affected your feet, make your doctor knows about any foot problems you are experiencing. This includes nail changes, pain when you walk, and morning stiffness. Getting the right diagnosis and treatment for your feet as early as possible is the best way to improve your quality of life and to keep you moving as much as possible.

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