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Diagnosis of tetanus
Last reviewed: 03.07.2025

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Early diagnosis of tetanus is based on the detection of trismus, sardonic smile and dysphagia. Later, rigidity of the muscles of the back of the head appears; hypertonicity spreads to other muscles of the body, technical convulsions join, the characteristic feature of which is the preservation of hypertonicity; muscles after the attack. Distinctive symptoms of tetanus are clear consciousness, fever, sweating and hypersalivation.
Indications for consultation with other specialists
If complications develop, consultation with other specialists is necessary. Thus, in case of fractures, tendon ruptures, massive bleeding, consultation with a surgeon is indicated, in case of convulsive syndrome, respiratory failure and multiple organ failure - consultation with a resuscitator.
Indications for hospitalization
If tetanus is suspected, patients are subject to emergency hospitalization in the intensive care unit due to possible disruption of vital functions and the need for intensive therapy and care.
Laboratory diagnostics of tetanus
Laboratory diagnostics of tetanus is of secondary importance. When clinical symptoms of the disease appear, the toxin in the blood cannot be detected even by the most sensitive methods. Detection of antitoxic antibodies has no diagnostic value, since it only indicates a history of vaccinations. With tetanus, there is no increase in antibody titers, since even lethal doses of exotoxin do not cause an immune response. In some cases, bacteriological methods are used (microscopy of smears, histological examination of tissue excised during surgical treatment of wounds, sowing of wound discharge on nutrient media under anaerobic conditions), which make it possible to detect the pathogen at the site of entry of infection. It is possible to isolate a culture of the pathogen from the wound in no more than 30% of patients.
Instrumental diagnostics of tetanus
Typically, there are no pathological changes in the cerebrospinal fluid.
Example of diagnosis formulation
Tetanus, generalized form, severe course. Complications: aspiration pneumonia, rupture of the right rectus abdominis muscle.
Differential diagnosis of tetanus
A similar clinical picture can be observed in patients with rabies, the distinctive features of which are confusion, psychomotor agitation, exophthalmos and mydriasis, short (several seconds) and frequent seizures, hydrophotoacuphobia, muscle relaxation in the interictal period. Trismus and "sardonic smile" are absent in rabies. On the 5-7th day of the disease, the disease passes into the paralytic stage, which inevitably ends in death.
Strychnine poisoning can be distinguished from tetanus by the presence of mydriasis, the ascending spread of convulsions, and the absence of tonic muscle tension. In strychnine poisoning, as in tetanus, generalized convulsions are observed, but between attacks there is complete relaxation of the muscles.
Tetany, which occurs with hypofunction of the parathyroid glands, differs from tetanus by affecting not only striated but also smooth muscles, gradual onset. With tetany, seizures are accompanied by vomiting, diarrhea, abdominal pain, bronchospasm. Convulsions very rarely become generalized and always affect small muscles of the extremities. Symptoms of Erb, Trousseau, Chvostek, "horse foot" and "obstetrician's hand" are revealed. Hypocalcemia is always detected.
An epileptic seizure, unlike the convulsive syndrome in tetanus, ends in sleep, complete relaxation of muscles, involuntary defecation and urination, and is characterized by retrograde amnesia.
Patients with hysteria can imitate a picture of a convulsive attack similar to tetanus, but after the attack, the mouse completely relaxes. The attack is accompanied by emotional reactions (crying, laughter), purposeful reactions (patients tear clothes, throw various objects, etc.). In difficult cases, a sleeping pill is prescribed, during which the muscles completely relax.
Less often, tetanus has to be differentiated from an exacerbation of widespread osteochondrosis, traumatic brain injury, and neuroinfections.