Post-Viral, Post-Chikungunya and Post-COVID Musculoskeletal Manifestations
DNB Orthopaedics • October 2024 • Paper IV • 10 Marks
Introduction
Viral infections may produce acute or persistent musculoskeletal symptoms through a combination of direct tissue injury, immune activation, cytokine-mediated inflammation, post-infectious autoimmunity and deconditioning.
The common clinical spectrum includes:
- Arthralgia
- Inflammatory arthritis
- Myalgia and myositis
- Enthesitis and tenosynovitis
- Post-infectious reactive arthritis
- Fatigue and generalized musculoskeletal pain
High-yield framework:
Think of post-viral musculoskeletal disease as virus-triggered inflammation that may outlast the acute infection.
A. Etiopathogenesis
1. Direct Viral Effects
Some viruses may directly infect or injure muscle, synovial tissue or vascular endothelium, producing local inflammation and pain.
- Muscle-fibre injury → myalgia / myositis
- Synovial activation → arthralgia / arthritis
- Endothelial injury → microvascular dysfunction and tissue inflammation
2. Immune-Mediated Inflammation
Viral infection activates innate and adaptive immunity with release of inflammatory mediators such as:
- Interleukin-1
- Interleukin-6
- TNF-α
- Interferons
- Other chemokines and inflammatory mediators
Persistent or dysregulated immune activation may cause symptoms even after viral clearance.
Mechanisms of Persistent Post-Viral Symptoms
Acute viral infection
↓
Innate + adaptive immune activation
↓
Cytokine release / tissue injury
↓
┌─────────────────────────────────────┐
│ Persistent immune activation │
│ Molecular mimicry │
│ Autoantibody formation │
│ Synovial…