What are the signs and symptoms of tetanus?

Signs and Symptoms of Tetanus

Tetanus typically presents with trismus (lockjaw), followed by generalized rigidity caused by painful contractions of skeletal muscles that can progress to respiratory failure and autonomic instability, which can be fatal. 1

Primary Clinical Manifestations

Early Signs and Symptoms

• Trismus (lockjaw) - difficulty opening the mouth, often the first specific sign
• Dysphagia - difficulty swallowing
• Sialorrhea - excessive salivation
• Neck and back stiffness/pain - common early presenting symptoms 2
• Facial muscle rigidity - may include risus sardonicus (characteristic facial expression with raised eyebrows and corners of the mouth drawn back)

Disease Progression

• Generalized muscle rigidity - affects limbs and paraspinal muscles
• Painful muscle spasms - triggered by touch, pain, bright light, or sounds 3
• Opisthotonic posture - severe hyperextension and spasticity of muscles causing arching of the back
• Respiratory compromise - can lead to apnea during severe spasms

Severe Disease Features

• Autonomic dysfunction - a hallmark of severe tetanus, includes:
  • Labile hypertension
  • Tachycardia
  • Increased secretions
  • Profuse sweating
  • Urinary retention 3
  • Dysautonomic crises with catecholamine surges (up to 100-fold increases in serum adrenaline) 4

Clinical Course

The incubation period from injury to symptom onset ranges from 3 to 21 days (median: 7 days), with extremes of 1 day to several months. Shorter incubation periods correlate with more severe disease and poorer prognosis 1.

The disease typically follows this pattern:

1. Prodromal phase: general malaise, mild fever, indolence, and anorexia 5
2. Development of trismus and dysphagia
3. Progression to generalized muscle rigidity and spasms
4. In severe cases, development of autonomic instability

The disease course is usually intense for ≥4 weeks before subsiding, with a protracted convalescent period 1.

Important Clinical Considerations

Risk Factors

• Unvaccinated or inadequately vaccinated individuals
• Persons with unknown or uncertain vaccination history 1
• Older adults (particularly those ≥65 years) have higher risk for both disease and mortality 1
• Entry of C. tetani spores through:
  • Deep puncture wounds
  • Wounds with necrotic tissue
  • Contaminated wounds exposed to soil or animal excrement 1
  • Injection drug use (significant risk factor) 2

Diagnostic Pitfalls

• The prodromal stage may lack the characteristic muscle spasms, leading to delayed diagnosis 5
• Tetanus is a clinical diagnosis - there are no laboratory tests to confirm infection
• Early symptoms may be mistaken for other conditions like dental problems, pharyngitis, or neurological disorders
• In developed countries, low clinical suspicion due to rarity of cases may delay diagnosis

Mortality Risk

• Case-fatality ratio for tetanus is highest in infants and the elderly
• Can be as high as 100% without high-quality medical care
• Even with modern healthcare, mortality remains approximately 10-20% 1
• Mortality is often related to respiratory complications and autonomic dysfunction

Neonatal Tetanus

Neonatal tetanus presents differently:

• Occurs from C. tetani infection of the umbilical stump
• Affects infants born to mothers with insufficient tetanus immunity
• Initially presents with poor feeding and irritability
• Progresses to rigidity, spasms, and opisthotonus

Early recognition of tetanus signs and symptoms is crucial for prompt treatment, as the disease can rapidly progress to life-threatening complications. Immediate administration of tetanus immune globulin, appropriate wound care, antimicrobial therapy, and intensive supportive care are essential for improving outcomes.