Source: Verywell Health; By Catherine Moyer, DPM, Updated on February 27, 2022
Rheumatoid arthritis (RA) can strike any part of your body, and that includes your feet. In fact, foot inflammation and pain is an early symptom for many people.
Foot symptoms in RA can take many forms. You may have pain in the joints or constant aching. You may also have pain in your ligaments, which are the bands of tissue that connect your bones to each other. Symptoms are often worse after standing for a long time, walking, or running.
For some people with RA, the onset of foot pain is gradual. For others, it is immediate. At some point, though, most people with RA find that foot joint pain makes it very painful to walk.
This article will discuss foot pain as a symptom of rheumatoid arthritis. It will also describe some of the strategies you can use to manage foot pain when you have RA.
How RA Affects Feet
Rheumatoid arthritis is an autoimmune condition. When you have RA, your immune system tries to destroy the lining of your joints, called synovium. It also attacks the fluid in your joints, called synovial fluid. It does this because it mistakes these parts of your body for disease-causing invaders.
RA causes damage and inflammation that makes your joints swell and feel warm.2 The small joints, like those in the feet, are the most common targets of these attacks.
Eventually, long-term inflammation thickens the synovium. This causes cartilage and bone to wear away. In the feet and toes, the joints may become deformed. This leads to poor range of motion and considerable pain. Walking, standing, and even wearing shoes can become difficult.
Proper treatment may help reduce the damage and inflammation to your foot joints. It may also prevent or delay deformities and other problems.
Is It RA or Osteoarthritis?
When you first notice foot pain, you may wonder if it's osteoarthritis (OA). OA is also known as wear-and-tear arthritis, and it is more common than rheumatoid arthritis.
There is no clear-cut way to tell if you have OA or RA without a medical diagnosis. But OA and RA do have some key differences.
RA Foot Pain
Usually affects both feet at once
Morning stiffness generally lasts longer than half an hour3
OA Foot Pain
Most often affects only one foot
Stiffness tends to be easier to relieve in the morning, often getting better in less than half an hour or with a few minutes of stretching
RA and Foot Deformities
In the feet, rheumatoid arthritis typically affects the metatarsophalangeal (MTP) joints of the toes. These are the joints that connect your toes to your feet.
RA can cause serious foot deformities. This is especially true if it goes untreated.
Lateral drift: Over time, the toes may "drift" outward, toward the little toe.4 This is sometimes called a lateral drift or lateral deviation. It looks like the toes are leaning.
Bunions: The feet may develop bunions (hallux valgus). These are painful bony lumps on the side of the foot by the big toe.
Contractures: RA may also cause your forefoot to shift. This can lead to contractures. A contracture is a permanent shortening of muscles or tendons in your toes. A well-known type of contracture is hammertoes. In this condition, the toe is permanently flexed and curled under. Contractures can lead to calluses and pain under the ball of the foot.
Flat feet: The talonavicular joint, which is part of the foot's arch, can become destabilized. When this happens, the arch may collapse.1
All these changes to a foot's structure and shape can make finding a comfortable shoe more difficult.
Other Foot Problems in RA
People with RA can have foot symptoms that aren't related to deformities. This is because the disease can impact almost any joint in the foot.
This is a common recurring problem for people with RA. It can occur at the back or underside of the heel.
Inflammation in the feet may lead to conditions associated with heel pain, including:
Plantar fasciitis, also called heel spur syndrome, which causes pain in the heel and the bottom of your arch
Achilles tendonitis, inflammation of the tendon that connects your calf muscle to your heel
Retrocalcaneal bursitis, when a fluid-filled sac (bursa) behind the heel bone, becomes inflamed and causes pain and swelling
Nerve Entrapment Syndromes
When RA inflames the synovium, the swelling can compress nerves. One example of this is tarsal tunnel syndrome. This causes burning, tingling, or shooting pain in the foot's arch and sole.
A rheumatoid nodule is a lump beneath the skin. It usually appears over a tendon or a bone located just below the skin's surface.
In the foot, a rheumatoid nodule may appear over the Achilles tendon. If a bunion is present, it may also appear on the side of the big toe.
Inflammation caused by RA can affect small blood vessels. This may lead to rashes or sores on the lower legs and feet.
Splinter hemorrhages are also possible. These are small areas of broken blood vessels on the sides of your toenails or fingernails.
Recap RA can cause foot deformities and other types of foot problems, including heel pain, nerve pain, nodules on the bones and tendons, and skin rashes.
Managing Foot Pain in RA
Getting treatment for RA can help relieve your foot pain and prevent deformities. This usually involves prescription medications to stop the immune system from attacking your joints. You may also need to find other ways to manage your foot pain and cope with deformities.
Common strategies include:
Anti-inflammatory drugs (NSAIDs)
Therapeutic footwear, or special shoes designed for people with RA
Foot orthotics, shoe inserts that can help provide support and reduce pain
Occupational therapy,3 which can help you with daily activities
The success of these strategies will depend on which joints are affected and to what degree. If these approaches don't work, you may need to consider surgery. Deformities like bunions and hammertoes can often be surgically treated.
For some cases, a doctor can fuse bones that form a joint. This involves connecting bones together permanently, which limits motion and reduces pain. Depending on which bones are fused, you may or may not notice the loss of motion.1
Recap RA treatment can help improve foot-related symptoms and prevent deformities. Other strategies include pain control with NSAIDs, steroid injections, therapeutic footwear, occupational therapy, and sometimes surgery.