RHEUMATOID ARTHRITIS | SOUTH TEXAS FOOT SPECIALIST
Rheumatoid arthritis is a chronic inflammatory disorder that attacks joints, but may also affect other tissues. It mainly affects synovial tissue which is the lining of the joints or joint capsule, the tissue surrounding the joint. It affects women three times more often than men. It is an autoimmune disease, that is, a disease in which the body develops an immune response against its own tissue. See: http://www.arthritis.org/about-arthritis/types/rheumatoid-arthritis/
This disease process can affect tissues other than joints, that is, extra-ariticular manifestations. Heel pain caused by rheumatoid arthritis can occur early in the disease process, before there is joint pain. Such heel pain is not mechanical in nature like plantar fasciitis so the level of physical activity may not affect this. Rheumatoid arthritis may cause "morning stiffness" so this may be similar or confused with the "first step" pain encountered with plantar fasciitis.
The diagnosis of rheumatoid arthritis may be assisted by lab tests. The traditional lab test for RA is known as rheumatoid factor (RF). A positive rheumatoid factor is present in about 75 to 80% of patients with rheumatoid arthritis but can also be found in some patients with chronic bacterial infections as well as some viral infections and parasitic diseases. A newer test is the anti-CCP antibody (anticyclic citrullinated peptide antibody) and is more specific than the RF.
The reasons why rheumatoid arthritis can cause heel pain are not understood. X-rays may show bone erosions. A more recent study performed via diagnostic ultrasound revealed the possibility of rupture of the membranes (septae) which hold the heel pad together underneath the heel bone. There is a thick cushion of fat tissue under the heel bone held together by fibrous cells or septae. Diagnostic ultrasound or sonography has become the "gold standard" for the examination of heel pain.
For more information on Pediatric Podiatry in the San Antonio, TX area, call Ed Davis, DPM, FACFAS at (210) 490-3668 today!