What is psoriatic arthritis?

Psoriatic arthritis (PsA) is a type of inflammatory arthritis that affects people with psoriasis. Psoriasis is a condition that causes red patches of skin with silvery scales.

According to the National Psoriasis Foundation, 30% of people with psoriasis develop PsA at some point. PsA causes pain, swelling, and tenderness in your joints.

PsA shares many symptoms with other types of inflammatory arthritis, such as rheumatoid arthritis, but it also has specific hallmarks. These hallmarks include problems in the feet, toes, and toenails.

PsA can cause a variety of problems in the feet, including pain and swelling in the toes, ankles, heels, and soles.

Swelling of the toes

A common feature of PsA in your feet is the swelling of one or more toes. This condition is known as dactylitis of the toes. The swelling tends to affect your entire toe rather than a single joint.

Tenosynovitis, or inflammation of the tendon sheath, is largely responsible for the swelling. It can give your toe a sausage-like appearance, sometimes referred to as “sausage toe.”

Swelling of the ankles

You may also notice swelling in the ankles or heels.

Swelling is sometimes accompanied by color changes, especially the development of a red or purple tint. Swollen areas may be warm to the touch and extremely tender.

Heel pain

People with PsA often develop a condition known as enthesitis. This refers to inflammation at a point where tendons and ligaments connect with bone. In people with PsA, enthesitis frequently affects the Achilles tendon. The Achilles tendon is the hard band connecting your heel to your calf muscles.

You may experience tenderness and pain at the back of your heel or notice swelling in your ankle. You may also notice stiffness in your ankle in the morning or after periods of rest.

Pain on the soles of the feet

Enthesitis can also cause pain in the soles of your feet. The plantar fascia is a sheet of connective tissue on the bottom of the foot that attaches your heel to the front of your foot. It runs along the bottom of your feet.

If you have pain and tenderness at the bottom of your heel, especially after waking, this may be the cause.

Inflammation of this connective tissue is also known as plantar fasciitis. It’s a common condition that regularly affects people with and without PsA.

Nail changes

Nail problems are common among people with PsA, especially those with nail psoriasis. You might notice your nails have pitting, ridges, flaking, discoloration, or lifting of the nail (onycholysis). You might also find that you develop more bacterial or fungal infections in your nails.

Nail changes occur as a result of inflammation and cellular disruption caused by PsA.

The goal of treating PsA is to reduce pain and prevent permanent bone damage. Without treatment, the feet can become permanently damaged. A number of medications can help reduce inflammation and protect your joints, including those in your feet.

Common medications for PsA include:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs): NSAIDs, such as ibuprofen (Advil, Motrin) and naproxen (Aleve), help reduce inflammation and treat pain.
  • Disease-modifying antirheumatic drugs (DMARDs): DMARDs, such as methotrexate (Trexall), leflunomide (Arava), sulfasalazine (Azulfidine), tofacitinib (Xeljanz), and apremilast (Otezla), work to prevent PsA from permanently damaging the joints.
  • Biologic agents: Biologics are a newer generation of arthritis drugs, formed through genetic engineering, that target inflammation in the body.

PsA symptoms in the feet are managed with oral medications mentioned above based on the severity of symptoms. These drugs treat inflammation throughout the body, including the feet and heels.

However, for severe flare-ups in the feet, you may want to consider a more localized approach, such as:

  • Cortisone injections: Cortisone injections can be given directly into your heels, the soles of your feet, or a single inflamed toe. They can reduce inflammation and treat painful flare-ups.
  • Ice: Ice can also help reduce inflammation in the joints of the feet. Roll your foot on a frozen water bottle wrapped in a towel or apply an ice pack to the affected area for 20 minutes. You can repeat the process two to four times a day.
  • Medicated foot powders: Cracks in your nails or skin can provide an opening for infections that can trigger PsA flare-ups. A medicated foot powder can help control moisture while addressing fungus and bacteria.
  • Night splints: A night splint prevents you from relaxing your plantar fascia while you sleep, which may help prevent heel pain.
  • Custom orthotics: Orthotics are inserts for your shoes that help you maintain a good posture while protecting the joints of your feet. They’re designed specifically for you to relieve foot, ankle, and heel pain.

Other steps you can take to manage PsA symptoms in your feet and prevent future flare-ups include:

  • consulting a podiatrist (foot doctor) in addition to your rheumatologist (arthritis doctor) and dermatologist (skin doctor)
  • avoiding ill-fitting shoes that may trigger flare-ups
  • wearing shoes with high and wide toe boxes, extra cushioning, wide sizes, and removable inserts
  • using over-the-counter heel pads or heel cups to add cushioning and support to your shoes
  • wearing compression socks to reduce and control swelling
  • maintaining a moderate weight, which helps reduce the amount of stress on the joints in your feet

PsA can lead to a range of uncomfortable symptoms in your feet. There are several medications that can help manage PsA symptoms. You can also take steps at home to reduce pain and your risk of flaring up. Talk with your healthcare team to learn more about supportive steps you can take in managing PsA.