Most rheumatologists tend to divide arthritis into two major categories: inflammatory and non-inflammatory. The latter category is also termed “degenerative” arthritis.

The major distinction is that inflammatory types of arthritis have a significant amount of inflammatory cells that attack the joints. These types of arthritis tend to cause more symptoms, particularly stiffness and pain. They also tend to be progressive. Oftentimes inflammatory types of arthritis are associated with constitutional symptoms, meaning low grade fever, weight loss, and fatigue. Inflammatory types of arthritis can also cause significant damage to internal organs. Disability and early death may be a consequence of some types of inflammatory arthritis. Examples of inflammatory arthritis are rheumatoid arthritis, systemic lupus erythematosus, psoriatic arthritis, gout, infectious arthritis, and ankylosing spondylitis.

Inflammatory types of arthritis can strike at any age.

Inflammatory types of arthritis have typical patterns although theoretically any joint in the body can be affected.

Inflammatory forms of arthritis may not be easy to categorize. Sometimes it will be obvious that inflammation is present and is a prominent component of the symptom complex. However, a specific diagnosis may not be apparent. Eventually most forms of inflammatory arthritis do “declare” themselves and ultimately fall into a category. But not always! This is a situation where a skilled diagnostician and clinician is worth their weight in gold!

On the other hand, non-inflammatory types of arthritis cause symptoms based on mechanical factors. Often degenerative arthritis affects weight-bearing joints such as the neck, low back, hips, and knees. It tends to occur in older people. While it may progress, it does so relatively slowly. It is rarely, if ever, associated with constitutional symptoms. In fact if constitutional symptoms are present, then either the patient has more than non-inflammatory arthritis or has another illness in addition to their arthritis. This is the type of arthritis people often associate with getting older.

Non-inflammatory types of arthritis may also be confusing some times. An example is a condition like fibromyalgia where the pain occurs pretty much all over. Symptomatic and subjective joint swelling may make the clinical diagnosis difficult.

The distinction between inflammatory and non-inflammatory arthritis is made on the basis of a careful history, physical examination, laboratory tests, and imaging procedures such as magnetic resonance imaging (MRI) and ultrasound.

Sometimes a patient can have both types of arthritis. For instance it is not uncommon for a patient with longstanding rheumatoid arthritis to also have degenerative arthritis (osteoarthritis) in a knee or hip.

Interestingly, when an arthroscope (small telescope) is used to visualize the interior of a joint, almost all types of arthritis have an inflammatory component to them. The extent and type of inflammatory change though varies from disease to disease.

The treatment for inflammatory arthritis will vary. While anti-inflammatory medicines are sometimes helpful, it may be necessary to start disease modifying drug therapy. Again the skill and experience of the arthritis specialist is paramount in determining which direction to head. Obviously, if the inflammatory arthritis becomes more well-defined, then treatment becomes easier to define as well.

The key point to remember is that if you do have arthritis, it's important to seek the opinion of an expert arthritis specialist.