The feet and ankles can be affected by several types of arthritis, including osteoarthritis and inflammatory arthritis.
Osteoarthritis can affect any joint in the foot. Osteoarthritis is a chronic problem that may cause episodic pain and swelling in a joint or joints; it can also cause bone enlargement. As people get older, osteoarthritis can be linked to changes in the shape of feet, which may cause pain.
Osteoarthritis often affects the big toe joint. The joint will become stiffer and the range of movement will be reduced. Often the bones become larger and knobbly due to an overgrowth of new bone. These changes may accompany a bunion (a lump on the side of the big toe joint). You may also notice a bunionette (a lump on the side of the little toe joint).
Recent findings suggest that osteoarthritis is more common in the arch area of the foot than previously thought. Osteoarthritis can also develop in the ankle, but this is usually following a previous injury or damage to the joint from long-standing inflammatory arthritis. Osteoarthritis in the feet often accompanies osteoarthritis in other joints.
There are various forms of inflammatory arthritis, which can affect feet in different ways.
- Rheumatoid arthritis can affect many joints in the feet.
- Reactive arthritis usually affects the ankle or the area around the heel. It may also affect the toes, causing pain and swelling, which is known as dactylitis.
- Psoriatic arthritis often causes dactylitis.
- Gout most commonly affects the big toe joint. It is a very painful type of arthritis. Gout causes severe inflammation and makes the joint red, hot and swollen during an attack, which typically lasts one to two weeks. Without treatment, repeated attacks can cause permanent damage to the joint and lead to osteoarthritis. It is caused by the formation of urate crystals in a joint. However, gout can usually be well controlled with medications.
- Ankylosing spondylitis mainly affects the spine but may also affect the heels.
Apart from problems in the joints themselves, people with inflammatory arthritis may have inflammation and discomfort in the tendons and the other soft tissues in the feet. The part under or behind the heel where the tendons attach to the heel bone (the Achilles tendon) is quite often affected in this way.
Dactylitis causes pain and swelling, usually in just one or two of the toes and can be referred to as 'sausage toe'.
Connective tissue disease
Raynaud's phenomenon is a circulatory problem that causes the blood supply to certain parts of the body to be reduced, especially when exposed to cold conditions. It more commonly affects fingers, but it can also cause toes to temporarily go cold and numb and turn white, then blue, then red. These attacks often only last a few minutes, and moving into a warmer environment often stops the attack. Wearing warm gloves and socks may help to prevent an attack.
Raynaud's phenomenon can occur with the conditions:
Watch out for ulcers on the toes, or a colour change which doesn't go away as quickly as usual. These problems are usually very painful. If you develop one of these symptoms, you should see your doctor or contact your rheumatology nurse specialist as soon as possible.
Sometimes with lupus the joints and tendons are affected and you may notice that the toes drift outwards and the arches may flatten. This can be painful and may cause a feeling of stiffness after periods of rest.
Why does foot pain become persistent?
In most cases foot problems will not become persistent. Painful heels for instance can settle down spontaneously even after many months of causing trouble. Some foot problems though will go on to be persistent, osteoarthritis is a good example.
If you have foot symptoms that have persisted for more than three months it's worth seeking a professional opinion.