Posted on July 10, 2015
Inflammatory back pain
by: James Perruquet, MD
CCHC New Bern Internal Medicine Specialists
Low back pain is one of the most common complaints seen in the primary care office. It is reported that at least 80% of the general population will at one time or another during their lifetime experience significant back pain. The vast majority of these back pain episodes are related to muscle spasm or degenerative joint and disc disease of the lumbar spine or sacroiliac joints. Typically these “mechanical” back pain problems can be attributed to trauma and usually get better with rest and are worsened by activity. A much smaller percentage of patients, perhaps 0.5% – 1.0% of the population will experience “atypical” back symptoms which suggest “inflammatory back pain.” The hallmarks of inflammatory back pain that distinguish it from the more common types of mechanical back pain include:
1. Onset before age 40 and often by age 20
2. Insidious onset without specific inciting event
3. Present for greater than 3 months
4. Prolonged morning stiffness
5. Improves with activity
Treatment of these two types of back pain varies greatly underscoring the need for proper diagnosis.
The prototypic inflammatory back disease is Ankylosing Spondylitis, although there are several associated disorders which share similar features and are collectively known as “seronegative spondyloarthropathies.” The associated disorders include psoriatic spondylitis (associated with psoriasis), reactive arthritis (seen following infections of the gastrointestinal or genitourinary systems), as well as inflammatory bowel diseases such as Ulcerative Colitis and Crohn’s disease. In addition to sharing inflammatory back pain symptoms, these disorders collectively share other features that differentiate them from mechanical back pain and other inflammatory conditions such as Rheumatoid Arthritis (which essentially never causes back pain). These shared features include:
1. Predilection for young adults with increased severity in males
2. Familial aggregation due to association with a genetic marker known as HLA-B27 (which is seen in about 90% of Ankylosing Spondylitis patients, where as it is present in only 8% of the general Caucasian population). It should be noted that these conditions are seen less frequently in the American black population due to the decreased prevalence of this genetic marker which is only present in 2-3% of this group.
3. Negative blood work for rheumatoid factor and other auto antibodies
4. Predilection for the sacroiliac joints and spine
5. When peripheral joints are involved, it is often the large joints of the lower extremities in an asymmetric pattern (both sides of the body are not equally affected)
6. Tends to involve the enthesis (area of ligament and tendon insertion into bones) resulting in heel and Achilles tendon pain, as well as dactylitis (sausage like swelling of the digits) which is a diffuse swelling of fingers and toes, which is different than the isolated joint involvement seen in conditions such as Rheumatoid Arthritis
7. Involvement of extra-articular organ systems including:
a. Eyes – iritis
b. Skin – psoriasis and psoriasis-like rashes
c. Mucous membranes – ulcerations
d. Lung – pulmonary fibrosis
e. Cardiac – aortic insufficiency and cardiac conduction disturbances
Interviewing the patient for a history of these conditions, or a family history of these conditions is often helpful. On examination it is imperative to look for loss of spinal mobility by checking chest expansion and lumbar motion.
Laboratory studies provide very little help in making a diagnosis, although one may have a mild anemia and have an elevated sedimentation rate consistent with inflammation. Occasionally, obtaining the genetic marker HLA-B 27, can assist in making a diagnosis in difficult situations. X-rays are often very helpful, with abnormalities identified in the sacroiliac joints and lumbar spine, however these typically appear late, often after 10 years of disease duration. MRI studies are often able to identify the inflammatory changes in the sacroiliac joints much earlier in the disease course allowing for an earlier diagnosis and treatment intervention.
Management of these disorders consists of proper posture and extension exercises of the spine. Avoidance of smoking and treatment of any of the associated disorders is also of benefit. Nonsteroidal anti-inflammatory medication (ibuprofen, Naproxen, Indomethacin, Diclofenac, Celebrex, etc.) have been the primary therapeutic intervention for many decades. For those with inadequate control with these NSAIDs, Azulfidine was previously the agent of choice. Notably Plaquenil, Methotrexate, Arava, and Azathioprine have not demonstrated efficacy for these inflammatory spinal conditions. The major recent advance however, has been with the “biologic” medications (Enbrel, Humira, Simponi, Cimzia, Remicade) which have proven to be of tremendous benefit at providing relief from pain, stiffness, fatigue, and loss of function, and may altar the natural history of these disorders.
If you are experiencing the signs and symptoms of inflammatory back pain, such as the insidious onset of chronic back pain, worse on arising in the morning, and improving with activity, you should discuss with your physician the possibility of being evaluated for one of these treatable conditions.
Contact CCHC New Bern Internal Medicine Specialists at 252.633.5333 if you have any questions or would like to make an appointment.