Tetanus
Tetanus is a clinically diagnosed neurologic syndrome caused by Clostridium tetani toxin (tetanospasmin), which blocks inhibitory neurotransmitter release and produces trismus, risus sardonicus, opisthotonos, and autonomic instability. Treatment is hospitalization with tetanus immune globulin, wound debridement, benzodiazepines for spasm control, and airway support, since consciousness remains intact throughout.
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What this article covers
- Overview
Definition: tetanus is an acute, potentially fatal neurologic syndrome caused by the exotoxin tetanospasmin, produced by Clostridium tetani, a gram-positive, spore-forming, obligate anaerobic rod ubiquitous in soil.
- Epidemiology
Rare in immunized populations: in the United States, widespread immunization has reduced tetanus to fewer than 40 cases per year.
- Risk factors
Incomplete or unknown tetanus immunization: the dominant risk factor; tetanus by definition occurs in patients without adequate protective immunity.
- Pathophysiology
Toxin production: C tetani spores germinate in the anaerobic wound and the vegetative bacteria produce tetanospasmin, a zinc-dependent metalloprotease.
- Clinical features
This is a clinical diagnosis with no confirmatory laboratory or imaging finding; recognition rests entirely on the characteristic pattern of rigidity and spasm in a patient with a compatible wound history and inadequate immunization.
- Differential diagnosis
Neuroleptic malignant syndrome: rigidity can mimic tetanus, but fever, altered mental status, and a recent antipsychotic or antiemetic history distinguish it, whereas tetanus preserves consciousness.
- Diagnosis
Diagnosis is established clinically on history and exam alone, once the characteristic pattern below is confirmed; there is no confirmatory blood test, and wound culture is insensitive and should not delay treatment.
- Management
First/initial action, always: admit to a monitored intensive care setting in a quiet, dark, low-stimulation room, since sensory stimuli trigger severe spasms; secure the airway proactively if there…
- Complications
Respiratory failure: laryngospasm or diaphragmatic spasm can cause airway obstruction or ventilatory failure, historically the leading cause of death.
- Prognosis
Recovery is prolonged: because damaged nerve terminals must be replaced by new axonal sprouting, clinical recovery typically unfolds over several weeks even with optimal treatment.
- Prevention
Primary vaccination series: the DTaP series (diphtheria, tetanus, acellular pertussis) is given in five doses at 2, 4, 6, and 15 to 18 months, and 4 to 6 years.
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