What does a high erythrocyte sedimentation rate (ESR) indicate and how is it treated?

Erythrocyte Sedimentation Rate (ESR): Indications and Management

An elevated erythrocyte sedimentation rate (ESR) is a non-specific marker of inflammation that indicates the presence of an underlying inflammatory, infectious, malignant, or autoimmune condition requiring further diagnostic evaluation based on clinical context. 1

What is ESR?

ESR is a measure of how quickly red blood cells settle in a tube of blood over a specified time period (usually one hour). It serves as a surrogate marker of inflammation, with normal values varying by age and gender:

• Men: <15 mm/hr under 50 years, <20 mm/hr over 50 years
• Women: <20 mm/hr under 50 years, <30 mm/hr over 50 years 1

Clinical Significance of Elevated ESR

An elevated ESR can indicate several conditions:

1. Inflammatory disorders:

   • Rheumatoid arthritis
   • Polymyalgia rheumatica
   • Temporal arteritis/Giant cell arteritis
   • Inflammatory bowel disease

2. Infectious diseases:

   • Osteomyelitis (markedly elevated ESR)
   • Prosthetic joint infections (ESR >35 mm/hr) 1
   • Kawasaki disease 2

3. Malignancies:

   • Hodgkin's lymphoma (risk factor for disease progression) 1
   • Multiple myeloma

4. Connective tissue disorders:

   • Systemic lupus erythematosus
   • Vasculitis

Limitations of ESR Testing

• ESR is non-specific and can be elevated in many conditions
• Clinical experience suggests that KD (Kawasaki Disease) is unlikely if ESR, CRP, and platelet count are normal after day 7 of illness 2
• Finding of a minimally elevated ESR in the setting of severe clinical disease should prompt investigation for disseminated intravascular coagulation 2
• ESR is elevated by IVIG therapy, making it less useful for monitoring response to treatment 2
• Many factors can result in falsely high or low ESR levels 3

Complementary Role of ESR and CRP

• ESR: Reflects fibrinogen levels with a longer half-life, making it more useful for monitoring chronic inflammatory conditions 3
• CRP: Has a shorter half-life, making it more useful for diagnosis and monitoring responses to therapy in acute inflammatory conditions 3
• Using both ESR and CRP provides complementary information 1

Approach to Elevated ESR

1. Interpret in clinical context:

   • An isolated elevated ESR without symptoms rarely indicates serious disease 1
   • ESR should be considered alongside clinical presentation and other laboratory findings

2. Consider common causes based on patient presentation:

   • In patients with joint pain: Consider rheumatoid arthritis, polymyalgia rheumatica, or other inflammatory arthropathies 2
   • In patients with headache (especially temporal): Consider giant cell arteritis 2
   • In patients with fever and rash in children: Consider Kawasaki disease 2
   • In patients with prosthetic joints and pain: Consider infection 2

3. Additional testing based on clinical suspicion:

   • Autoantibody testing (RF, ACPA) if inflammatory arthritis is suspected 2
   • Temporal artery biopsy if giant cell arteritis is suspected 2
   • Joint aspiration if septic arthritis or prosthetic joint infection is suspected 2

Treatment Approach

Treatment should be directed at the underlying cause rather than the elevated ESR itself:

1. Inflammatory conditions: Anti-inflammatory medications, disease-modifying antirheumatic drugs, or biologics depending on the specific diagnosis
2. Infections: Appropriate antimicrobial therapy
3. Malignancies: Oncology referral and treatment specific to the malignancy
4. Monitoring: Serial ESR measurements are useful for monitoring disease activity and treatment response 1

When to Refer

• Unexplained persistently elevated ESR despite initial workup
• Signs of temporal arteritis (headache, jaw claudication, visual symptoms) require urgent referral 2
• Suspected inflammatory arthritis should be referred to rheumatology 2
• Suspected malignancy should be referred to appropriate specialist

Key Points to Remember

• ESR is not a useful screening test in asymptomatic individuals 4
• ESR may be normal in some patients with cancer, infection, and connective tissue disease 4
• ESR is most useful in diagnosing temporal arteritis and monitoring response to treatment 4
• In rheumatoid arthritis, ESR has limited diagnostic value but may help monitor disease activity 4