Tetanus is an acute, frequently fatal spasmodic disease resulting from a wound infected with the organism Clostridium tetani. The disease is exotoxin mediated. In the United States, 69% of Americans > 70 years old not have adequate immunity. The incidence has increased in the 20 to 59 years old.
As a result of an injury, C. tetani and its spores are introduced into the wound. Devitalized tissue, if any, favors toxin formation. The incubation varies from 24 hours to more than 30 days. The spores can germinate and release the toxin. Most injuries are unrecognized, and vary from puncture wounds, surgical procedures, abortions, or in neonates because of inadequate umbilical cord care. Clinically, tetanus is categorized into 4 forms: local, generalized, cephalic, and neonatal.
Local tetanus presents with rigidity of muscles in proximity to the injury site and usually resolves without sequelae. Generalized tetanus is the most common and presents with pain and stiffness in the jaw. Later, the rigidity leads to the development of trismus and the characteristic facial expression, risus sardonicus, “sarcastic grimace.” Violent spasms and tonic contractions of muscle groups are responsible for the symptoms of the disease including dysphagia, opisthotonos, flexing of the arms, fist clenching, and extension of the lower extremities. Importantly, mentation remains normal, unless laryngospasm and chest rigidity cause respiratory compromise.
In the second week of the illness, a hypersympathetic state develops and manifests as tachycardia, hypertension, sweating, and hyperpyrexia, this difficult to manage hyperactivity contributes to the morbidity and mortality.
Cephalic tetanus follows injuries to the head and neck, can result in dysfunction of cranial nerves, most often the seventh nerve, it has a poor prognosis.
Neonatal tetanus carries an extremely high mortality rate and results from inadequate maternal immunization and poor umbilical cord care.
Diagnosis and Differential
Tetanus is diagnosed clinically. Prior immunization does not eliminate tetanus as a diagnostic possibility. There are not any confirmatory laboratory tests. The differential diagnosis includes strychnine poisoning, dystonic reactions to phenothiazine, hypocalcemic tetany, rabies, peritonsillar abscess, peritonitis, meningitis, SAH and TMJ disease.
Emergency Department Care and Disposition
Patients with tetanus are best managed in an intensive care unit due to the potential for respiratory compromise. Environmental stimuli must be minimized to prevent precipitation of convulsive spasms. Identification and debridement of the inciting wound and devitalized tissue, after immune globulin administration, is necessary to minimize further toxin production.
Tetanus immune globulin 3000 to 6000 units IM in a single injection should be given, in the opposite site of the toxoid administration. It should be given before any wound debridement because more exotoxin may be released during wound manipulation.
Tetanus toxoid (DTap or Td depending on age), 0.5 mL IM at presentation, and 6 weeks and 6 months after presentation (see Chapter 16).