What are the symptoms of tetanus?

Symptoms of Tetanus

Tetanus typically presents with trismus (lockjaw), followed by generalized rigidity caused by painful contractions of skeletal muscles that can impair respiratory function, potentially leading to glottic spasm, respiratory failure, and autonomic instability which can result in death. 1

Initial Presentation and Progression

• The incubation period from injury to symptom onset varies from 3 to 21 days (median: 7 days), with extremes of 1 day to several months 1
• Shorter incubation periods are associated with more severe disease and poorer prognosis 1
• Longer incubation periods are associated with injuries furthest from the central nervous system 1

Early Symptoms

• Trismus (lockjaw) is present in approximately 75% of patients and is typically the first symptom 2
• Dysphagia (difficulty swallowing) 3
• Neck stiffness and pain 4
• Facial muscle spasms, sometimes producing a characteristic "risus sardonicus" (sardonic smile) 3

Progressive Symptoms

• Generalized muscle rigidity affecting limbs and paraspinal muscles 3
• Painful muscle spasms triggered by touch, pain, bright light, or sounds 3
• Opisthotonic posture (severe hyperextension and spasticity with arching of the back) 3
• Reflex spasms occur in 70% of patients and characterize the severity of the disease 2
• Abdominal rigidity (may mimic an acute abdomen) 5

Severe Manifestations

• Laryngeal spasms that can compromise the airway 3
• Respiratory muscle involvement leading to respiratory compromise 3
• Autonomic instability characterized by:
  • Labile hypertension and tachycardia 3
  • Increased secretions and sweating 3
  • Urinary retention 3
  • Dysautonomia (severe autonomic dysfunction) which is difficult to manage and is a common cause of mortality 3
• Severe spasms may produce apnea and rhabdomyolysis 3

Course and Prognosis

• The disease course is usually intense for ≥4 weeks before subsiding 1
• The convalescent period is typically protracted 1
• Long-term neurologic sequelae and intellectual and behavioral abnormalities might follow recovery 1
• The case-fatality ratio for tetanus is highest in infants and the elderly 1
• Mortality can be as high as 100% without high-quality medical care, but remains approximately 10–20% even in modern healthcare facilities 1
• The case-fatality ratio for reported tetanus in the United States declined from 18% (1998-2000) to 8.0% (2001-2016) 1

Important Clinical Considerations

• Tetanus occurs almost exclusively among persons who are unvaccinated or inadequately vaccinated, or in those whose vaccination histories are unknown or uncertain 1
• Older adults are at higher risk, with lower prevalence of protective antibody levels (45% of men and only 21% of women aged >70 years) 6
• Unusual presentations can occur, such as tetanus masquerading as an acute abdomen with abdominal pain and rigidity 5
• Tetanus does not confer natural immunity, so patients must complete a full primary immunization series after recovery 7