Tetanus is an acute and frequently fatal disease resulting from an infection with the organism Clostridium tetani. The disease is exotoxin mediated and can occur after any of a variety of tissue injuries, including clean and contaminated wounds, elective surgery, burns, puncture wounds, otitis media, dental infections, animal bites, abortion, and pregnancy. Due to successful vaccination campaigns, tetanus is a rare disease in developed countries but remains a significant problem elsewhere in the world.
C. tetani is prevalent throughout the environment in soil, dust, skin surfaces, and animal and human feces. Spores are resistant to destruction, survive years on environmental surfaces, and are introduced into the body following tissue injury. Anaerobic tissue conditions lead to toxin formation when the spores begin to germinate, and therefore crushed or devitalized tissue, a retained foreign body, or infection can favor growth of the toxin-producing form of C. tetani. The incubation period ranges from <24 hours to >1 month, and while most cases occur within 14 days some patients may present several months after injury. Many cases of tetatnus occur in patients where no specific injury is recognized, and injuries are often minor and occur indoors.
Clinically, tetanus is categorized into three forms: local, cephalic, and generalized. Local tetanus is uncommon and presents with persistent muscle contractions in proximity to the injury site. Cephalic tetanus is rare, occurs occasionally with otitis media or head injuries, and has localized involvement of the face and cranial nerves. Generalized tetanus is the most common form (80% of cases) and often presents with a descending pattern of symptoms that begin with pain and stiffness in the jaw. Progression of the symptoms leads to trismus (lockjaw) and development of the classically described facial expression, risus sardonicus. 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, rigidity of abdominal muscles, and extension of the lower extremities. Autonomic symptoms include fever, sweating, hypertension, and tachycardia. Neonatal tetanus is a form of generalized tetanus and can occur due to inadequate maternal immunization and poor umbilical cord care, with symptoms typically presenting by the second week of life and associated with an extremely high mortality rate.
Diagnosis and Differential
Tetanus is diagnosed clinically, and early symptoms may include trismus, neck stiffness or sore throat, and dysphagia. The tetanospasmin toxin interferes with central and peripheral nervous system inhibitory pathways leading to unopposed muscle contraction, seizures, and autonomic nervous system dysfunction. Prior immunization does not eliminate tetanus as a diagnostic possibility. There are no confirmatory laboratory tests. Other potential diagnoses with muscular contraction or other symptoms that may be similar to tetatnus include strychnine poisoning, dystonic reactions to phenothiazine, hypocalcemic tetany, rabies, peritonsillar abscess, peritonitis, and meningitis.
Emergency Department Care and Disposition