Tetanus (lockjaw) is an acute disease caused by neurotoxins from the bacterium Clostridium tetani. C. tetani is ubiquitous in spore form and enters the body through broken skin (e.g., deep puncture wounds). Its toxins then cause uncontrolled activation of alpha motor neurons, leading to muscular rigidity and spasms. Patients classically present with a triad of trismus, risus sardonicus, and opisthotonus. Tetanus is a clinical diagnosis, but diagnostic testing may help confirm the diagnosis. Treatment includes airway management, wound debridement, immunoglobulin therapy (e.g., ), antibiotics (e.g., metronidazole), and pharmacological management of severe muscle spasms. Prevention of tetanus involves routine immunization with tetanus vaccines and administering postexposure prophylaxis for wounds.
Route of infection
- Clostridial spores contaminate a wound (e.g., through dirt, saliva, feces).
- Localized ischemia, necrosis, foreign bodies and/or coinfection with other bacteria predispose to infection.
- Wounds with compromised blood supply create anaerobic conditions that are required for the germination and multiplication of C. tetani.
- Groups with a higher risk: : non-immunized individuals, those with diabetes, neonates, people who inject drugs (PWID), certain patient groups (i.e., postsurgical, obstetric, dental)
Tetanospasmin: reaches the CNS through retrograde axonal transport
- Toxin binds to receptors of peripheral nerves and is then transported to interneurons (Renshaw cells) in the CNS via vesicles. 
- Acts as protease that cleaves synaptobrevin, a SNARE protein → prevention of inhibitory neurotransmitters (i.e., GABA and glycine) release from Renshaw cells in the spinal cord → uninhibited activation of → muscle spasms, rigidity, and autonomic instability
- Tetanolysin: causes hemolysis and has cardiotoxic effects
Tetanospasmin causes tetanic spasms.
- Incubation period: 3–21 days (average: ∼ 10 days)
Generalized tetanus: painful muscle spasms and rigidity
- Trismus: lockjaw due to spasms of jaw musculature (commonly the first tetanus-specific symptom)
- Risus sardonicus: sustained facial muscle spasm that causes a characteristic, apparently sardonic grin and raised eyebrows
- Opisthotonus: backward arching of spine, neck, and head caused by spasms of the back muscles
- Neck stiffness
- Abdominal rigidity
- Life-threatening complications
Subtypes and variants
- Occurs in infants of inadequately immunized mothers after unsterile management of the umbilical stump
- Typically occurs 5–8 days after birth, but the incubation period can take up to several weeks
- Typically a rapid onset of symptoms as axonal length in infants is shorter than in adults 
Other types 
- Immediately manage life-threatening and severe symptoms (see “Acute stabilization”).
- Administer passive immunization, e.g., , as soon as possible.
- , e.g.,
- Initiate antibiotics, preferably PO metronidazole.
- Admit all patients with suspected tetanus infection.
- ICU admission is often required. 
- Follow . 
- Begin active immunization; with the tetanus vaccine once the patient is improving.
Acute stabilization 
- Laryngospasm or respiratory muscle spasm: with RSI)  (
- Cardiac instabilit:
- Severe muscle spasms: benzodiazepines and/or paralytics; , potentially in combination with 
- Passive immunization: immunoglobulin therapy 
- Active immunization: administered at a separate site from HTIG 
Tetanus vaccine 
Routine immunization is recommended for all individuals.
- Active component: denatured tetanus toxin
- Children < 7 years of age
- Children ≥ 7 years of age and adults
- Schedule: See “ACIP immunization schedule” for details.
Acellular pertussis-containing vaccines are contraindicated in patients who previously developed unexplained encephalopathy within a week after receiving an acellular pertussis vaccine (i.e., DTaP or Tdap). 
Tetanus prophylaxis after injury 
- Management is based on:
- Immune status (e.g., HIV infection)  ,
Tetanus-prone wounds include:
- Deep injuries
|Postexposure tetanus prophylaxis |
|Tetanus vaccine history||Clean and minor wounds||Tetanus prone wounds|
Unknown or < 3 doses
|≥ 3 doses|