Tetanus Symptoms
Tetanus presents with progressive muscle rigidity beginning with trismus (lockjaw), followed by neck stiffness, dysphagia, and generalized muscle spasms that can be triggered by minor stimuli.
Cardinal Clinical Features
Early Symptoms
- Trismus (lockjaw) is the presenting symptom in approximately 75% of patients, manifesting as stiffness or spasms in the jaw muscles 1, 2, 3
- Neck stiffness and rigidity develop early in the disease course 4
- Dysphagia (difficulty swallowing) commonly occurs as the toxin affects pharyngeal muscles 2, 5
Progressive Muscle Involvement
- Muscle rigidity spreads from the jaw to the neck and then to the abdominal and limb muscles 2, 5
- Rigidity of paraspinal muscles produces the characteristic opisthotonic posture (severe backward arching of the back) 5
- Generalized muscle stiffness affects both limbs and trunk musculature 4, 5
Reflex Spasms
- Reflex spasms occur in approximately 70% of patients and characterize disease severity 3
- These severe tonic spasms are triggered by minor stimuli including touch, pain, bright light, or sounds 5
- Spasms can produce apnea (breathing cessation) and rhabdomyolysis (muscle breakdown) 5
- Laryngeal spasms may occur, threatening the airway 5
Severe Manifestations
Autonomic Dysfunction
- Autonomic overactivity develops in severe tetanus, causing labile hypertension, tachycardia, increased secretions, profuse sweating, and urinary retention 5
- This dysautonomia is difficult to manage and represents a common cause of mortality 5
Respiratory Complications
- Respiratory complications occur early in the disease course and require aggressive airway management 3
- Aspiration risk is significant due to dysphagia and laryngeal dysfunction 5
Temporal Characteristics
Incubation and Onset
- The incubation period from injury to symptom onset ranges from 3 to 21 days, with a median of 7 days (extremes: 1 day to several months) 1, 6
- Shorter incubation periods correlate with more severe disease and poorer prognosis 1, 6
- Longer incubation periods occur with injuries furthest from the central nervous system 1
Disease Course
- The disease course is typically intense for ≥4 weeks before subsiding 1
- The convalescent period is protracted 1
- Long-term neurologic sequelae and intellectual and behavioral abnormalities may follow recovery 1
Atypical Presentations
Diagnostic Pitfalls
- Tetanus can masquerade as an acute abdomen with abdominal pain and rigidity, posing a diagnostic dilemma 7
- The latency period can be prolonged (up to 45 days post-injury), making the connection to prior trauma less obvious 7
- Careful elicitation of contaminated injury history is critical when patients present with atypical symptoms 7
Underlying Pathophysiology
- Tetanospasmin (the tetanus toxin) prevents release of inhibitory neurotransmitter GABA in the spinal cord, brainstem motor nuclei, and brain, producing the characteristic muscle rigidity and spasms 6, 5
- The toxin binds irreversibly to neural tissue, explaining why symptoms persist despite treatment 6