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For further information, see CMDT Part 33-05: Clostridial Diseases

Key Features

Essentials of Diagnosis

  • History of wound with possible contamination

  • Jaw muscle stiffness ("lock jaw") then spasms (trismus)

  • Neck stiffness

  • Dysphagia

  • Irritability

  • Hyperreflexia

  • Finally, painful convulsions precipitated by minimal stimuli

General Considerations

  • Caused by the neurotoxin tetanospasmin elaborated by Clostridium tetani

  • Spores of this organism are ubiquitous in soil. When introduced into a wound, spores may germinate

  • Tetanospasmin interferes with neurotransmission at spinal synapses of inhibitory neurons

  • Minor stimuli result in uncontrolled spasms, and reflexes are exaggerated

  • Incubation period is 5 days to 15 weeks, with the average being 8–12 days

  • Most cases occur in unvaccinated individuals

  • Persons at risk

    • Elderly

    • Migrant workers

    • Newborns

    • Injection drug users, who may acquire the disease through subcutaneous injections

Clinical Findings

Symptoms and Signs

  • The first symptom may be pain and tingling at the site of inoculation, followed by spasticity of the muscles nearby

  • Other early signs

    • Stiffness of the jaw

    • Neck stiffness

    • Dysphagia

    • Irritability

  • Hyperreflexia develops later, with spasms of the jaw muscles (trismus) or facial muscles and rigidity and spasm of the muscles of the abdomen, neck, and back

  • Painful tonic convulsions precipitated by minor stimuli are common

  • Spasms of the glottis and respiratory muscles may cause acute asphyxia

  • The patient is awake and alert throughout the illness. The sensory examination is normal. The temperature is normal or only slightly elevated

  • Urinary retention and constipation may result from spasm of the sphincters

  • Respiratory arrest and cardiac failure are late, life-threatening events

Differential Diagnosis

  • Meningitis

  • Rabies

  • Tetany due to hypocalcemia

  • Strychnine poisoning

  • Neuroleptic malignant syndrome

  • Trismus due to peritonsillar abscess


  • The diagnosis is made clinically



  • Human tetanus immune globulin, 500 units, is given intramuscularly to those with clinical signs and symptoms of tetanus. Active immunization with tetanus toxoid should be started concurrently

  • Table 33–2 provides a guide to prophylactic management

  • Debridement of wounds should be undertaken if implicated as the source

  • Metronidazole 7.5 mg/kg administered intravenously or orally every 6 hours (maximum 4 g daily) is preferred and should be administered to all patients

  • Penicillin, 20 million units intravenously daily in divided doses, is an alternative

Table 33–2.Guide to tetanus prophylaxis in wound management.

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