Can viral infections cause an increase in Erythrocyte Sedimentation Rate (ESR)?

Viral Infections Can Increase Erythrocyte Sedimentation Rate (ESR)

Yes, viral infections can cause an increase in Erythrocyte Sedimentation Rate (ESR), though the elevation is typically less pronounced than in bacterial infections. 1

Mechanism and Pattern of ESR Elevation in Viral Infections

• ESR is a non-specific marker of inflammation that measures the rate at which red blood cells settle in a tube over a specified time period 2
• During viral infections, inflammatory responses trigger the production of acute phase reactants that can alter blood viscosity and red cell aggregation, leading to increased ESR values 1, 2
• Viral infections typically cause mild to moderate ESR elevations, while bacterial infections often cause more significant elevations 1, 3
• In post-viral rhinosinusitis, ESR may be elevated as part of the inflammatory response, though this finding alone cannot distinguish between viral and bacterial etiologies 1

Clinical Significance of ESR in Viral Infections

• ESR elevation in viral infections is generally less pronounced than in bacterial infections, with values typically below 70 mm/h 4, 5
• In a study of dengue hemorrhagic fever (viral infection), 77% of patients maintained normal ESR values (<20 mm/h), with only 23% showing any elevation 3
• The mean ESR in viral infections (20.46 mm/h) was significantly lower than in bacterial infections (34.81 mm/h) in comparative studies 3
• COVID-19 infection has been associated with ESR elevation, with studies showing increased values in both acute infection and long COVID 1

Diagnostic Value in Different Viral Conditions

• In COVID-19, ESR is included among laboratory tests that can help assess disease severity and inflammatory status 1
• In Multisystem Inflammatory Syndrome in Children (MIS-C) associated with SARS-CoV-2, elevated ESR is part of the diagnostic criteria and initial screening evaluation 1
• ESR has limited sensitivity as a standalone test for viral infections, making it more useful when interpreted alongside other clinical and laboratory findings 2, 6
• Some viral agents, particularly adenovirus or influenza virus, can cause invasive infection with inflammatory responses similar to bacterial infections, resulting in more pronounced ESR elevation 1

Clinical Applications and Limitations

• ESR should be used as a complementary test rather than a standalone diagnostic tool when evaluating for possible viral infections 6
• The degree of ESR elevation does not reliably distinguish between viral and bacterial etiologies, requiring additional clinical context and laboratory tests 1, 2
• In suspected post-viral rhinosinusitis, ESR may be elevated but has poor specificity for determining etiology 1
• ESR values should be interpreted with caution in patients with anemia, as low hematocrit can artificially elevate ESR independent of the underlying infection 2, 7

Monitoring and Follow-up

• Serial ESR measurements may be more informative than a single value in monitoring disease progression or response to treatment 6
• In viral infections that trigger autoimmune responses or prolonged inflammation, ESR may remain elevated during the recovery phase 1, 8
• ESR typically normalizes as the viral infection resolves, though this may take longer than the resolution of clinical symptoms 2
• Persistently elevated ESR after apparent clinical recovery from a viral infection may warrant further investigation for complications or secondary infections 6, 5