Bursitis: Systemic Causes, Diagnosis, and Management

What diseases cause bursitis?

Bursitis, while commonly associated with overuse or direct trauma, can also be a significant symptom or manifestation of various underlying systemic diseases, particularly inflammatory conditions, infections, and metabolic disorders.

Understanding Bursitis: More Than Just Overuse

Bursitis is the inflammation of a bursa, a small, fluid-filled sac that acts as a cushion between bones, tendons, muscles, and skin. These sacs reduce friction and facilitate smooth movement, particularly around joints. When a bursa becomes inflamed, it can cause pain, swelling, tenderness, and restricted movement in the affected area.

What is a Bursa? Our bodies contain over 150 bursae, strategically located at points of high friction. Common sites for bursitis include the shoulder (subacromial), elbow (olecranon), hip (trochanteric, iliopsoas), knee (prepatellar, infrapatellar, anserine), and heel (retrocalcaneal).

Common Causes of Bursitis The most frequent causes of bursitis are:

• Repetitive Motion or Overuse: Activities that involve repeated movements, such as throwing, kneeling, or prolonged sitting.
• Direct Trauma: A sudden impact or fall on a bursa.
• Prolonged Pressure: Sustained pressure on a bursa, like leaning on elbows.
• Poor Posture or Mechanics: Imbalances that increase stress on certain joints.

However, when bursitis recurs, is severe, or affects multiple sites without clear mechanical cause, it often signals an underlying systemic condition.

Systemic Diseases Linked to Bursitis

Several systemic diseases can directly cause or contribute to the development of bursitis. These conditions often involve widespread inflammation, immune system dysfunction, or metabolic abnormalities that affect connective tissues, including bursae.

Inflammatory Arthritis Conditions These autoimmune or inflammatory diseases are primary culprits, as they involve chronic inflammation that can extend to bursae.

• Rheumatoid Arthritis (RA): A chronic autoimmune disorder primarily affecting the lining of joints, causing painful swelling and bone erosion. Bursitis, particularly around the elbows (olecranon), shoulders, and hips, is a common extra-articular (outside the joint) manifestation of RA, driven by the systemic inflammatory response.
• Gout: A form of inflammatory arthritis caused by the deposition of uric acid crystals in the joints. While typically affecting small joints like the big toe, gout can also cause acute, painful inflammation in bursae, especially the olecranon (elbow) and prepatellar (knee) bursae, due to crystal deposition within the bursa itself.
• Pseudogout (Calcium Pyrophosphate Deposition Disease - CPPD): Similar to gout, but caused by the deposition of calcium pyrophosphate crystals. It can lead to acute inflammation in joints and bursae, mimicking gout or septic bursitis.
• Ankylosing Spondylitis and Psoriatic Arthritis (Spondyloarthropathies): These are types of inflammatory arthritis primarily affecting the spine and entheses (where tendons/ligaments attach to bone). However, they can also cause peripheral joint inflammation and bursitis, particularly in the hips, shoulders, and heels, as part of their systemic inflammatory pathology.

Infection-Related Conditions Bursitis can be caused by an infection that spreads to the bursa, leading to what is known as septic bursitis.

• Bacterial Infections: Most commonly caused by Staphylococcus aureus (staph) or Streptococcus bacteria. Bacteria can enter the bursa through a cut, scrape, insect bite, or puncture wound over the bursa. Less commonly, it can spread from an infection elsewhere in the body (hematogenous spread), especially in individuals with weakened immune systems. This is a medical emergency requiring prompt antibiotic treatment.

Metabolic and Endocrine Disorders Certain metabolic imbalances can predispose individuals to bursitis.

• Diabetes Mellitus: Individuals with diabetes are at a higher risk of developing various musculoskeletal issues, including adhesive capsulitis ("frozen shoulder"), tendinopathies, and bursitis. This increased susceptibility is thought to be due to microvascular changes, impaired tissue healing, altered collagen properties, and a higher propensity for infection.
• Thyroid Disorders (e.g., Hypothyroidism): An underactive thyroid can lead to musculoskeletal symptoms, including muscle aches, stiffness, and sometimes bursitis or tendinitis, possibly due to fluid retention and metabolic alterations affecting connective tissue health.

Other Systemic Conditions

• Lupus (Systemic Lupus Erythematosus - SLE): An autoimmune disease that can affect various organs and tissues, including joints and connective tissues. While less common than in RA, lupus can cause inflammatory bursitis as part of its widespread inflammatory nature.

Why Do These Diseases Cause Bursitis?

The mechanisms by which these systemic diseases lead to bursitis are varied but generally involve:

• Immune System Dysregulation: In autoimmune conditions like RA, lupus, or spondyloarthropathies, the immune system mistakenly attacks the body's own tissues, including the synovial lining of bursae, leading to chronic inflammation.
• Crystal Deposition: In gout and pseudogout, the presence of specific crystals (uric acid or calcium pyrophosphate) within the bursa triggers a powerful inflammatory response, causing acute pain and swelling.
• Infection Spread: In septic bursitis, microorganisms directly invade the bursa, leading to a localized inflammatory and infectious process.
• Metabolic Changes: Conditions like diabetes can alter the structural integrity and healing capacity of connective tissues, making bursae more susceptible to inflammation from minor trauma or overuse.

Diagnosis and Management Considerations

When bursitis is suspected to be due to a systemic disease, the diagnostic approach becomes more comprehensive than for simple overuse injuries.

Diagnostic Approach

• Detailed Medical History: Crucial for identifying pre-existing conditions, family history of autoimmune diseases, and risk factors for infection.
• Physical Examination: To assess the affected bursa and evaluate for other systemic signs.
• Laboratory Tests: Blood tests may be ordered to check for inflammatory markers (e.g., ESR, CRP), autoantibodies (e.g., rheumatoid factor, anti-CCP), uric acid levels, or signs of infection (e.g., white blood cell count).
• Imaging Studies: Ultrasound or MRI can help visualize the inflamed bursa and rule out other pathologies.
• Bursal Fluid Aspiration: In cases of suspected septic bursitis or crystal-induced bursitis, fluid may be aspirated from the bursa for analysis (cell count, Gram stain, culture, crystal analysis).

Treatment Focus Management of bursitis caused by systemic diseases involves not only addressing the localized inflammation but, crucially, treating the underlying systemic condition.

• Localized Treatment: Rest, ice, compression, elevation (RICE), NSAIDs, physical therapy, and corticosteroid injections (with caution in septic cases).
• Systemic Treatment: Medications targeting the underlying disease, such as disease-modifying antirheumatic drugs (DMARDs) for RA, urate-lowering therapy for gout, or antibiotics for septic bursitis.

Conclusion: A Holistic View of Joint Health

While overuse and trauma remain leading causes, understanding that bursitis can signal deeper systemic issues is vital for both fitness professionals and individuals. Recognizing these connections allows for a more comprehensive diagnostic approach and more effective, targeted treatment strategies, ultimately supporting overall joint health and well-being. If you experience persistent or recurrent bursitis, especially without a clear mechanical cause, consult a healthcare professional to explore potential underlying systemic conditions.