Tetanus (Generalized)

Generalized Tetanus — Emergency Medicine & Primary Care Summary

Generalized tetanus is a life-threatening, vaccine-preventable neurological infection caused by the neurotoxin (tetanospasmin) of Clostridium tetani. It is characterized by widespread painful muscle spasms, rigidity, trismus, and autonomic dysfunction, and constitutes a medical emergency requiring ICU-level care.[1-2]

1. History

• Port of entry: Ask about any wound, cut, abrasion, puncture, or skin break in the preceding 3 weeks (incubation period 3–21 days, median ~7 days); also ask about motorbike accidents, piercings, acupuncture, subcutaneous/intramuscular injections, dental procedures, and chronic skin ulcers[2-3]
• Up to 30% of patients have no identifiable wound at presentation[2]
• Symptom characterization: Jaw stiffness (trismus/lockjaw) → neck stiffness → back/abdominal pain → generalized rigidity → painful spasms triggered by noise, light, or touch[2]
• Timing: Onset typically cephalocaudal; spasms peak in the second week of illness[2]
• Period of onset (first symptom → first spasm): <48 hours = poor prognosis[4]
• Vaccination history: Determine primary series completion, last booster, and any prior tetanus episodes; tetanus can occur even in partially vaccinated individuals[3]
• Important negatives: Preserved consciousness (lucidity is maintained — obtundation suggests an alternative diagnosis), no sensory deficits[2]

2. Alarm Features

• Respiratory compromise: Dyspnoea, apnoeic spells, laryngospasm — risk of sudden airway obstruction[2][4]
• Autonomic nervous system dysfunction (ANSD): Labile blood pressure, tachycardia alternating with bradycardia, profuse sweating, fever >40°C — the most feared complication and leading cause of death in ventilated patients[2]
• Rapid symptom evolution: Incubation period <7 days and period of onset <48 hours predict severe disease[3-4]
• Severe dysphagia with aspiration risk[2]
• Opisthotonus (extreme hyperextension) — a late and ominous sign[2]
• Rhabdomyolysis from prolonged spasms → acute kidney injury[3]
• Cardiovascular events: Takotsubo cardiomyopathy (most common cardiac complication), arrhythmias, sudden cardiac arrest — occur days 5–20 of illness[5]

3. Medications

Acute Treatment

• Human tetanus immunoglobulin (hTIG): 500 IU IM (single dose); equine antitoxin if hTIG unavailable[2-3]
• Metronidazole: 500 mg IV q6h × 10 days (preferred antibiotic; penicillin is an alternative but may theoretically worsen spasms via GABA antagonism)[1][3]
• Benzodiazepines (first-line spasm control): Diazepam 10–30 mg IV q1–4h PRN, or midazolam infusion; doses often exceed 1 mg/kg/day of diazepam[2-3]
• Neuromuscular blocking agents (severe/refractory spasms): Vecuronium or rocuronium preferred (cardiovascularly inert); requires mechanical ventilation[2-3]
• Propofol: Second-line sedation/spasm control[3]
• Magnesium sulfate: Adjunct for spasm control and autonomic dysfunction[3-4]
• Labetalol: For sympathetic hyperactivity[3]
• Intrathecal baclofen: Considered for refractory spasms, though not widely practiced[2-3]

Medications to Avoid/Use with Caution

• Pancuronium (exacerbates autonomic instability)[3]
• Phenothiazines (lower seizure threshold, rarely used)[2]

Vaccination

• Administer Td or Tdap 0.5 mL IM on admission regardless of prior vaccination status; tetanus does not confer natural immunity — a full immunization course is required after recovery[2-3]

4. Diet

• NPO initially in patients with significant trismus or dysphagia due to aspiration risk[3]
• Enteral feeding via soft, small-bore nasogastric tube or parenteral nutrition via central venous catheter as soon as feasible[3]
• Hydration: Aggressive IV fluid management; patients have high metabolic demands from sustained muscle contraction and sweating
• Long-term: Resume oral diet only after spasms and dysphagia have resolved

5. Review of Systems

• Neurological: Jaw stiffness, difficulty opening mouth, difficulty swallowing, voice changes, back pain, abdominal pain, muscle stiffness/spasms; preserved consciousness[2]
• Respiratory: Dyspnoea, choking episodes, apnoeic spells
• Cardiovascular: Palpitations, chest pain (Takotsubo), diaphoresis[5]
• GU: Urinary retention (autonomic dysfunction)[2]
• GI: Abdominal rigidity (can mimic acute abdomen), fecal incontinence[2-3]
• Constitutional: Fever (if early/high-grade, consider alternative diagnosis or superinfection)[2]

6. Collateral History and Family History

• Collateral: Confirm vaccination records; obtain details of wound/injury from witnesses; inquire about injection drug use, gardening/farming activities, animal exposure[2]
• Family history: Not directly hereditary, but household vaccination status and shared environmental exposures (rural, agricultural) are relevant
• Social context: Rural residence, farming occupation, low socioeconomic status, and injection drug use are strongly associated[2][6]

7. Risk Factors

• Incomplete or absent vaccination (most important risk factor) — 95% of patients in some series had no prior immunization[7]
• Older age (waning immunity; elderly have lowest seroprotection rates)[2]
• Male sex[2]
• Rural residence / farming / gardening injuries[2][6]
• Injection drug use (skin-popping)[2]
• Immunosuppression (diabetes, HIV, chronic steroid use)[2-3]
• Chronic wounds (venous ulcers, diabetic foot ulcers)[8]
• Penetrating wounds, crush injuries, burns, surgical wounds[4]
• Comorbidities: Diabetes, cardiovascular disease worsen prognosis[3]

8. Differential Diagnosis

• Strychnine poisoning — virtually indistinguishable; rapid onset (<30 min of ingestion); absence of tonic contraction between spasms; positive serum/urine assay[2]
• Neuroleptic malignant syndrome (NMS) — altered mental status, gradual onset, very high CK, medication history[2]
• Drug-induced dystonia (phenothiazines, metoclopramide) — absence of trismus, rapid response to anticholinergics (procyclidine/diphenhydramine)[2][4]
• Hypocalcemic tetany — low serum calcium, absence of trismus, Chvostek/Trousseau signs[2]
• Stiff-person syndrome — positive GAD antibodies, absence of trismus[2]
• Progressive encephalomyelitis with rigidity and myoclonus (PERM) — positive anti-glycine antibodies, altered mental status[2]
• Cerebral malaria — altered mental status, seizures, parasitemia on smear[2]
• Peritonitis/acute abdomen — rigid abdomen from tetanus can mimic surgical abdomen; unnecessary laparotomies have been reported[2-3]
• Meningitis — fever, altered mental status, CSF abnormalities (CSF is normal in tetanus)[3]
• Key distinguishing feature of tetanus: Preserved consciousness with trismus + generalized rigidity + stimulus-provoked spasms[2]

9. Past Medical History

• Prior tetanus episodes (does NOT confer immunity — full re-vaccination required)[2]
• Vaccination history (primary series, last booster)
• Chronic wounds, recent surgeries (including colorectal surgery — documented as a rare portal of entry)[3]
• Diabetes, immunosuppressive conditions
• Injection drug use history
• Prior ICU admissions, intubation history

10. Physical Exam

Vital Signs

• Tachycardia (HR >120 bpm in severe disease), labile blood pressure, fever (late or suggests superinfection), tachypnea (RR >30–40)[4]

Key Findings

• Trismus (lockjaw) — present in 93–98% at admission[4]
• Risus sardonicus — sustained facial muscle spasm producing a grimacing smile[2]
• Generalized rigidity — board-like abdominal rigidity persisting between spasms[2][4]
• Opisthotonus — arched back from extensor spasm (late sign)[2]
• Hyper-reflexia with bilateral hypertonia[2]
• Stimulus-provoked spasms — triggered by noise, light, or touch[2]
• Preserved sensorium — patient is alert and oriented[2]
• Wound inspection: Look for any wound, even minor/healed; check extremities, feet, chronic ulcers

Concerning Findings

• Apnoeic spells, stridor, or inability to handle secretions → impending airway loss
• Profuse diaphoresis, urinary retention → autonomic dysfunction[2]

11. Lab Studies

Recommended Labs

• CBC (mild leukocytosis common; neutrophilia = poor prognostic indicator)[2]
• BMP (electrolytes, BUN, creatinine — assess for AKI)[3]
• Creatine kinase (elevated from rhabdomyolysis)[2-3]
• Calcium (to exclude hypocalcemic tetany)[2]
• Magnesium (baseline and monitoring during MgSO₄ therapy)[2]
• CRP, procalcitonin (to assess for superinfection; CRP usually moderately elevated)[2-3]
• Urinalysis — assess for myoglobinuria (proxy for rhabdomyolysis)[2]
• Blood gas analysis[2]
• LFTs[2]

Rule-Out Labs

• Serum/urine strychnine assay if poisoning suspected[2]
• Serum calcium to exclude tetany[2]
• Anti-GAD and anti-glycine receptor antibodies if stiff-person syndrome or PERM suspected[2]
• No confirmatory test exists for tetanus — diagnosis is clinical[1][3]

12. Imaging

• Imaging is generally unnecessary for diagnosis[2]
• Wound CT: May identify foreign bodies or gas locules if wound source unclear[2]
• Chest X-ray: Baseline and to assess for aspiration pneumonia
• Neuroimaging/lumbar puncture: Usually unnecessary; CSF is normal in tetanus. Consider only if meningitis or encephalitis is in the differential[2-3]
• Echocardiography: If cardiovascular instability develops — screen for Takotsubo cardiomyopathy[5]

13. Special Tests

Severity Scoring

Modified Ablett Classification (most widely used)

• Grade 1 (Mild): Mild trismus, spasticity, no spasms, no respiratory compromise
• Grade 2 (Moderate): Moderate trismus, marked rigidity, short spasms, RR >30
• Grade 3 (Severe): Severe trismus, prolonged reflex spasms, RR >40, apnoeic spells, HR >120
• Grade 4 (Very Severe): Grade 3 features + violent autonomic disturbances (labile BP, alternating tachy/bradycardia)
• Tetanus Severity Score (TSS): Includes age, dyspnoea, time to admission, comorbidities, entry site, BP, fever; AUC 0.89 — outperforms Phillips and Dakar scores[3-4]

Microbiological (supportive only)

• RT-PCR for C. tetani neurotoxin gene from wound tissue[2]
• Wound culture (low yield; C. tetani is difficult to culture and can be present without disease)[2-3]
• Spatula test: No longer recommended due to risk of precipitating laryngospasm[2]

14. ECG

• Obtain ECG on all patients — cardiovascular events occur in ~10.8% of tetanus patients[5]
• Sinus tachycardia — most common finding (autonomic hyperactivity)
• Labile heart rate — alternating tachycardia and bradycardia[2][4]
• ST-segment changes / T-wave inversions — may indicate Takotsubo cardiomyopathy or myocardial infarction[5]
• Arrhythmias — second most common cardiovascular event (19.4% of cardiac events)[5]
• Sudden cardiac arrest — reported in 16.1% of cardiovascular events; often from catecholamine surge[5]
• Continuous telemetry is essential throughout ICU stay

15. Assessment

• Generalized tetanus is the most common and most severe form of adult tetanus[2-3]
• Clinical diagnosis — no confirmatory test; based on trismus + generalized rigidity + stimulus-provoked spasms with preserved consciousness[1][3]
• Severity stratification via Ablett classification guides management intensity; 60% of patients in some series present as Grade 4 (very severe)[7]
• Atypical presentations: Isolated rigid abdomen mimicking acute abdomen; voice changes as early symptom; absence of identifiable wound in up to 30%[2-3]
• Complications: Respiratory failure, ANSD, Takotsubo cardiomyopathy, rhabdomyolysis/AKI, aspiration pneumonia, nosocomial infections, VTE, fractures from spasms, PRES[2-3][5]
• Case fatality rate: ~5–50% depending on access to ICU care; as low as 2.4% in well-resourced, high-volume centers; ~10–20% in modern facilities[2][9]
• Recovery takes 4–6 weeks for inhibitory neurotransmission to be restored[2]

16. Treatment Plan

Immediate Stabilization (ED)

• Airway: Assess for laryngospasm/airway compromise; prepare for early intubation if severe trismus, dysphagia, or apnoeic spells[2-3]
• IV benzodiazepines: Diazepam 10–30 mg IV, repeat q1–4h PRN for spasm control[3]
• Minimize stimulation: Quiet, dark room; limit noise, light, and physical contact[1][3]

First Day of Treatment

• hTIG 500 IU IM (single dose)[3]
• Td or Tdap 0.5 mL IM (at a different site from hTIG)[3]
• Metronidazole 500 mg IV q6h × 10 days[3]
• Wound debridement if applicable[3]
• Enteral feeding via NG tube or parenteral nutrition[3]

ICU Management

• Titrate benzodiazepine infusion; escalate to neuromuscular blockade (vecuronium/rocuronium) if spasms refractory — requires mechanical ventilation[2-3]
• Autonomic dysfunction: Magnesium sulfate IV infusion or labetalol; arterial line and invasive hemodynamic monitoring[3]
• DVT prophylaxis: Prophylactic heparin[3]
• Echocardiography if hemodynamic instability — screen for Takotsubo[5]
• Bedside physical therapy initiated early[3]
• Benzodiazepine taper over 14–21 days once spasms diminish[3]

Pre-Discharge

• Administer another dose of Td/Tdap before discharge; complete full vaccination series[3]
• Physical therapy and supportive psychotherapy[3]

17. Disposition

• All suspected generalized tetanus → ICU admission, even for mild (Ablett Grade 1) disease — early ICU admission is recommended given unpredictable progression[2]
• Mechanical ventilation required in 65–90% of severe cases; median duration ~16–21 days[2][7]
• Median hospital stay: ~22–30 days (longer for severe disease)[6-7]
• Specialist consultation triggers: Critical care/intensivist (mandatory), infectious disease, surgery (wound debridement), cardiology (if cardiovascular events), nephrology (if AKI)
• Discharge criteria: Resolution of spasms, stable autonomic function, tolerating oral intake, completed initial vaccination doses, adequate functional status

18. Follow Up / Return Precautions

• Complete the full tetanus vaccination series after discharge (natural infection does NOT confer immunity)[2-3]
• Follow-up timing: Outpatient visit within 1–2 weeks of discharge; ongoing physical therapy
• Expected recovery: Protracted — full neurological recovery takes 4–6 weeks minimum; most patients recover fully with sustained supportive care, even elderly patients[2]
• Return precautions: New or worsening muscle stiffness/spasms, difficulty breathing or swallowing, chest pain, palpitations, fever, decreased urine output, falls
• Long-term outcomes: 61% of ICU survivors had no lasting disability at ~4 years in one cohort; 35% required discharge to non-home settings initially[2]
• Patient counseling: Emphasize that tetanus can recur — lifelong booster adherence (Td every 10 years) is essential

References

1. What Is Tetanus?. — Zhou S, Malani P. The Journal of the American Medical Association. 2026.

2. Tetanus: Recognition and Management. — Sudarshan R, Sayo AR, Renner DR, et al. The Lancet. Infectious Diseases. 2025.

3. Tetanus. — Ergönül Ö, Kolsuz S, Figueroa JP. Lancet. 2026.

4. Tetanus. — Yen LM, Thwaites CL. Lancet. 2019.

5. Magnitude, Patterns, and Associated Predictors of Cardiovascular Events in Tetanus: A 2-Year, Single-Center, Ambidirectional Cohort Study Involving 572 Patients. — Pham OKN, Tran BN, Duong MC, et al. Open Forum Infectious Diseases. 2023.

6. Management and Outcome of Adult Generalized Tetanus Patients in a Tertiary Hospital in Anhui, China: A Retrospective Study. — Huang J, Cai E, Ding W, et al. Frontiers in Public Health. 2025.

7. Management and Outcome of Adult Generalized Tetanus in a Chinese Tertiary Hospital. — An Y, Guo Y, Li L, et al. Frontiers in Public Health. 2023.

8. Video NeuroImage: Generalized Tetanus in a 70-Year-Old Woman. — De Marchis GM. Neurology. 2008.

9. Prevention of Pertussis, Tetanus, and Diphtheria With Vaccines in the United States: Recommendations of the Advisory Committee on Immunization Practices (ACIP). — Liang JL, Tiwari T, Moro P, et al. MMWR. Recommendations and Reports : Morbidity and Mortality Weekly Report. Recommendations and Reports. 2018.