Tetanus

Key Features

Essentials of Diagnosis

• Nonimmunized or partially immunized patient

• History of skin wound

• Spasms of jaw muscles (trismus)

• Stiffness of neck, back, and abdominal muscles, with hyperirritability and hyperreflexia

• Episodic, generalized muscle contractions

• Diagnosis is based on clinical findings and the immunization history

General Considerations

• Caused by Clostridium tetani

• In unimmunized or incompletely immunized individuals, infection follows contamination of a wound by soil containing clostridial spores from animal manure

• Two-thirds of cases in the United States follow minor puncture wounds of the hands or feet

• In many cases, no history of a wound can be obtained

• Injecting substances and drug abuse may be risk factors (in individuals who are not tetanus-immune)

• In the newborn, usually in underdeveloped countries, infection generally results from contamination of the umbilical cord

• Incubation period typically is 4–14 days but may be longer

• In the United States, cases in young children are due to failure to immunize

Clinical Findings

Symptoms and Signs

• First symptom often is mild pain at the site of the wound, followed by hypertonicity and spasm of the regional muscles

• Characteristically, difficulty in opening the mouth (trismus) is evident within 48 hours

• In newborns, the first signs are irritability and inability to nurse

• The infant may then develop stiffness of the jaw and neck, increasing dysphagia, and generalized hyperreflexia with rigidity and spasms of all muscles of the abdomen and back (opisthotonos)

• Facial distortion resembles a grimace (risus sardonicus)

• Difficulty in swallowing and convulsions triggered by minimal stimuli such as sound, light, or movement may occur

• Individual spasms may last seconds or minutes; recurrent spasms are seen several times each hour, or they may be almost continuous

• In most cases, the temperature is normal or only mildly elevated

• A high or subnormal temperature is a bad prognostic sign

• Patients are fully conscious and lucid

• A profound circulatory disturbance associated with sympathetic overactivity (elevated blood pressure, tachycardia, arrhythmia) may occur on the second to fourth day, which may contribute to the mortality rate

Differential Diagnosis

• Bacterial meningitis

• Phenothiazine reactions

• Decerebrate posturing

• Narcotic withdrawal

• Spondylitis

• Hypocalcemic tetany

Diagnosis

• Clinical

• There may be a mild polymorphonuclear leukocytosis

• CSF is normal with the exception of mild elevation of opening pressure

• Serum muscle enzymes may be elevated

• Anaerobic culture and microscopic examination of pus from the wound can be helpful, but C tetani is difficult to grow, and the drumstick-shaped gram-positive bacilli often cannot be found

Treatment

General Measures

• Treatment best accomplished in an intensive care unit

• Patient is kept in a quiet room with minimal stimulation

• Control of spasms and prevention of hypoxic episodes are crucial

• Benzodiazepines can be used to help control ...