How Does Psoriatic Arthritis Affect the Feet?
In addition, some people with psoriatic arthritis experience pain at the arch of the foot or in the heel. This type of pain is caused by enthesitis, the inflammation caused by psoriatic arthritis at the attachment points of the tendons and ligaments.
When enthesitis occurs at the arch of the foot, it is called plantar fasciitis. Enthesitis at the heel is called Achilles tendonitis. Finally, the nails of the toes can become affected by psoriatic arthritis, causing pitting, thickening, lifting of the nail from the nail bed, and pain.1,2
Psoriatic arthritis foot pain
The initial symptoms of psoriatic arthritis in the feet are pain, swelling, warmth, and stiffness. Patients may notice the need to change shoe height, weight or width several times a day. Walking can become difficult with stiffness and swelling.3
Plantar fasciitis is the inflammation of a thick band of connective tissue that runs from the bottom of the heel bone to the toes. It is characterized by pain that feels like the arch of the foot is tearing, and the pain is often worse in the morning or after a period of inactivity.2,3
Achilles tendonitis is characterized by the inflammation, heat and pain in the tendon running from the heel up to the calf. The pain may improve slightly with initial activity but worsens with exercise.4
Diagnosing psoriatic arthritis in the feet
Physicians will examine a patient’s feet during a physical examination. The patient may be asked to walk while being watched. Imaging with x-rays, ultrasound, or MRI may also be performed to view the joints in the feet.2,3
Treatment of psoriatic arthritis in the feet
As with all symptoms of psoriatic arthritis, treating the foot symptoms begins with treating the underlying disease. Minor pain and stiffness of mild PsA can be alleviated with non-steroidal anti-inflammatory drugs (NSAIDs). In addition, injections of corticosteroids may be used.5
Medication options for PsA
For moderate to severe disease, treatments that target joint disease in PsA can reduce symptoms and prevent disease progression. Recommended treatments include disease-modifying anti-rheumatic drugs (known as DMARDs). The first step for treatments is usually DMARDs such as methotrexate, leflunomide, or sulfasalazine.
Other treatments include medicines that target tumor necrosis factor (TNF), a chemical that produces a wide range of inflammation in PsA. Examples of TNF blockers include etanercept (Enbrel), adalimumab (Humira), infliximab (Remicade), golimumab (Simponi), and certolizumab pegol (Cimzia).
Other DMARDs that have proven effective in clinical trials include ustekinumab (Stelara), brodalumab (which is awaiting FDA approval), and secukinumab (Cosentyx).6 The FDA has also recently approved Inflectra (infliximab-dyyb), a biosimilar to infliximab, for the treatment of psoriatic arthritis.8
Physical therapy as a treatment option
Physical therapy, involving exercises, stretching, heat, cold, and possible vocational readjustments, can be a critical treatment approach to protect the involved joints and maintain function.5,7
Proper footwear to manage PsA symptoms in the feet
Proper footwear is also recommended to ease foot pain. Open-toed shoes or shoes with a large toe box can provide more room for swollen toes. High heels are not recommended, as they can cause additional stress on the toes. Adding cushioned shoe inserts or wearing thick soles with extra cushioning can help provide extra support.2