Psoriatic Arthritis in Feet: What it Looks Like

Psoriatic arthritis (PsA) can affect the joints of the feet and ankles, as well as the structures supporting the joint. According to the National Psoriasis Foundation, up to 50% of people living with PsA also experience inflammation where the tendons and ligaments meet the foot bones.

PsA in the feet can make it hard to walk and perform activities of daily living. And while PsA has no cure, there are treatment options available to slow down the disease and relieve symptoms. With appropriate treatment, people with PsA can manage pain, stay active, and lead fulfilling lives. 

This article will help you understand how psoriatic arthritis affects your feet and what it can look like. It explains why a diagnosis of early-stage psoriatic arthritis and effective treatment can help to prevent more severe and systemic complications.

What Is Psoriatic Arthritis?

PsA is a form of inflammatory arthritis that often affects people with the autoimmune skin condition psoriasis. It can affect any of the joints of the foot, plus the ankle joints and the ligaments and tendons of the foot. It causes parts of the feet to become inflamed, sore, and tender. 

PsA affects people assigned male and female equally. According to the National Psoriasis Foundation, an estimated 30% of people with psoriasis also have PsA. Psoriasis affects 2% to 3% of the world’s population.

Causes and Risk Factors

Foot involvement in PsA can cause significant pain and difficulty with walking, especially in the morning and after sitting for a long period. PsA is also associated with many different foot conditions, including dactylitis, Achilles tendonitis, plantar fasciitis, and arthritis mutilans.

• Dactylitis is severe inflammation around the finger or toe joints. Severe inflammation can make the digits look like sausages. Severe dactylitis can cause the toes to be so rigid that it can be difficult and painful to flex them.
• Achilles tendonitis occurs when the tendon connecting the calf muscles (the Achilles tendon) to the heel becomes painful or inflamed where it attaches to the heel bone.
• Plantar fasciitis causes inflammation at the place where the plantar fascia (the soft tissue under the foot) attaches to the heel bone.
• Arthritis mutilans is a complication of PsA. It is characterized by severe inflammation that damages the joints of the hands and feet, resulting in deformity and disability.
  

What Does It Look Like?

Psoriatic arthritis can affect the heels and ankles, the toes, and the middle or top of the foot.

Arthritis in the Heel and Ankle

The ankle can be a source of severe pain and instability when it is affected by PsA. Symptoms of PsA in the heel might include:

• Stiffness upon awakening in the morning
• Recurring pain in the heel
• Swelling of the heel
• Limited movement
• Skin changes, including rashes and growths

Inflammation at the heel can cause impacts where tendons or ligaments attach to bones. It can lead to conditions that cause heel pain that include retrocalcaneal bursitis, a condition in which the bursa (the fluid-filled sac at the heel bone) becomes inflamed, causing pain and swelling.

Additional symptoms of PsA in the ankle include swelling and stiffness of the ankle and problems with mobility. The condition will eventually affect gait—the way a person walks.

PsA in the Toes

PsA in the toes is often the result of wear and tear of the cartilage in the toe joints or inflammation of the toe joints. The big toe is most often affected, but other toes can also be involved.

Common symptoms of PsA of the toes may include pain that can take hours or days to resolve, and swelling and inflammation in and around the toe joints. PsA can cause significant pain and swelling. Sometimes, the toes become so swollen that they can resemble sausages (dactylitis).

Additional symptoms of PsA in the toes might include:

• Restricted range of motion due to swelling or cartilage damage
• Development of bone spurs, which can further restrict movement
• Difficulty and pain with bending the toes
• A toe that might bend permanently downward
• Pain that worsens with weight-bearing activity—running, walking, climbing stairs, etc.
• A bump formation or sore
• Pitted, separated, thickened toenails
• Curling of toes—hammertoe or claw toe

Claw Toes

Claw toes are a condition in which the toes bend into a claw-like position. Claw toes are not a serious problem on their own, but they are generally a sign of an underlying condition like PsA.

You should call your doctor if your toes show signs of becoming clawed. Your toes may seem flexible early on, but they can become stuck in this position permanently over time. Treatment is important to keep this from happening.

PsA in the Middle/Top of the Foot

PsA might affect the middle or top of the foot. In the midfoot, symptoms include pain and swelling that becomes worse with standing and walking.

Other Changes in Appearance

PsA can cause changes in the appearance of feet. These include skin and nail changes, bunions, and bursae inflammation.

Skin and Nail Changes

PsA can cause skin and nail changes. For example, rashes associated with PsA and psoriasis can occur anywhere on the body, including on the feet.

PsA is also associated with a condition called palmoplantar pustulosis, which can cause tiny, pus-filled blisters on the soles of the feet. Up to 80% of people with PsA will have nail involvement.

Nail changes include pitting (small indents in the nails), thickening, brittle nails, and onycholysis (nails separating from the nail bed).

Bunions

Bunions are bony bumps that form at the joint at the base of the big toe. They occur when the bones at the front part of the foot move out of place. This will cause the tip of the big toe to be pulled toward the smaller toes, forcing the joint at the base of the big toe to stand out. The skin covering the bunion can become red and sore.

Bursae

Bursae are thin, fluid-filled sacs that act as a cushion and reduce friction between bones and soft tissues like muscles, tendons, and skin. The foot and ankle have several bursae.

Conditions like PsA can cause the bursae to become inflamed, leading to a symptom called bursitis. Bursitis can cause pain, swelling, and redness. Bursa pain can be disabling and affects the ability to walk.

Symptoms of Psoriatic Arthritis in the Feet

The primary symptoms of psoriatic arthritis in the feet are swelling and joint pain/stiffness. With PsA, it's common to experience periods of symptom flare-up followed by periods of remission.

Swelling or Heat

Swelling and warmth are common characteristics of inflammation. When inflammatory arthritis affects the feet or the ankles, you may experience swelling of one or more joints of the feet, ankles, or toes. Abnormal warmth in one or more areas of the foot often accompanies swelling in the joints of the feet, even while the rest of the body remains generally cool.

Swelling is noticeable after a person has been sitting for a long time, or after they get out of bed in the morning. Swelling can make it hard to put on your shoes, and shoes may feel tight when you first start walking around.

Pain and Stiffness

Pain is one of the most common symptoms of PsA in the feet. You may feel general foot pain with stepping, pain in the toes, and/or pain only in the big toe.

Foot pain can be sharp or stabbing depending on the amount of inflammation or the level of damage in the foot. Pain can make it harder to do normal daily activities.

Locked Joint

Locked joints are typical when there is a lot of swelling and stiffness. Locking means that the joint is hard to bend. Rough edges on bones and bone spurs can also cause joints to lock up.

Toe joints can get locked up, which can be painful. Fortunately, a locked toe joint isn’t permanent. You can usually loosen a locked joint by walking around or manipulating the toe joint so it bends again.

 Stages of PSA in the Feet

Early Stages

Most people diagnosed with psoriatic arthritis (about 85% to 92%) experience signs and symptoms of psoriasis that occur seven to 10 years before arthritis symptoms emerge.

It may be helpful to watch for certain symptoms of early-stage psoriatic arthritis in the feet, to help arrive at an early diagnosis and treatment. They include:

• Nail psoriasis, especially with pitting on the nail
• Skin lesions at the intergluteal cleft (the groove in your lower back and then buttocks)
• Uveitis (a type of eye inflammation)

Mid Stages

With progression of psoriatic arthritis, you may experience more joint pain and swelling in your feet. The pain and swelling also can occur in other parts of the body, including the neck and hips.

Other symptoms can include:

• Fatigue
• Low-grade fever
• Increasing joint stiffness, deformity, and mobility problems

Late Stages

In the late stages of psoriatic arthritis, you may experience considerable pain as joints become damaged. This can lead to permanent changes. Other serious consequences can occur with untreated PsA as it advances. These include:

• Diarrhea and other gastrointestinal (digestive health) problems
• Coughing and difficulty breathing due to lung effects of PsA
• Damage to the heart and blood vessels 
• Weak bones and the risk of osteoporosis
  

Diagnosis

If you have symptoms of psoriatic arthritis, see your healthcare provider. It is important to get a diagnosis right away since untreated psoriatic arthritis can cause permanent damage to your joints.

Your healthcare provider will look for swollen joints and toes, skin and nail changes, and pain in your toes and feet. You may need an imaging test such as an X-ray, CT scan, or ultrasound. Blood tests can help rule out other types of arthritis such as gout and rheumatoid arthritis. A blood test can also tell your healthcare provider if you have inflammation.

If you haven't already been diagnosed with psoriasis, your healthcare provider may do a skin test to confirm that you have the condition.

Treatment

Your healthcare provider might recommend different therapies to treat PsA in your feet. These might include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce swelling
• Steroid medications to be injected into the affected joints
• Custom-made shoes, shoe inserts, or arch supports to support your ankles and feet
• Physical therapy that includes foot exercises and stretches

Your healthcare provider might also recommend surgery if other treatments don’t work to manage your condition. Surgical options might include:

• Arthrodesis: Also called fusion surgery, this involves fusing bones together with rods, pins, screws, or plates. When bones heal, the bones will stay joined.
• Joint replacement surgery: Also called arthroplasty, this surgery is used only in severe cases. The surgeon will take out damaged bones and cartilage and replace them with metal and plastic.
  

Coping

There are many things you can do at home to help cope with the pain and discomfort of PsA in your feet. These include:

• Creams containing capsaicin or menthol: These creams may stop the nerves from sending out pain signals.
• Hot or cold packs in the affected areas
• Gentle exercises, including yoga and tai chi
• Foot massage

Making changes to your lifestyle can also help you feel better and keep the condition from getting worse. Lifestyle changes might include choosing low-impact exercises like swimming rather than high-impact ones (e.g., jogging), maintaining a healthy weight to keep stress off joints, and reducing or avoiding activities that trigger symptoms in the feet and ankles.

Summary

Psoriatic arthritis can cause pain, swelling, stiffness, and other foot symptoms. It may also cause your toes to become claw-shaped or sausage-like. The nails may develop thickening and pitting.

PsA foot and ankle pain can be debilitating, but it is treatable. Reach out to your healthcare provider if you experience symptoms or see a visible deformity in your foot. Your healthcare provider may prescribe medications like NSAIDs or steroid injections to help treat your psoriatic arthritis. If these treatments don't work, you may need surgery.

You can cope with psoriatic arthritis symptoms in your feet by applying pain relieving creams, using hot or cold packs, and modifying your lifestyle to include low-impact exercises. Maintaining a healthy weight can also help.