Tetanus is a life-threatening, vaccine-preventable neurological disease caused by the neurotoxin of Clostridium tetani, characterized by muscle spasms, rigidity, and autonomic dysfunction. It is a medical emergency requiring ICU-level care. [1-2]
1. History
- Port of entry: Ask about recent wounds (puncture, crush, burns, abrasions), dental procedures, otitis media, surgical wounds, injection drug use, or umbilical stump care (neonates) [1][3]
- Incubation period: Time from injury to first symptom — typically 3–21 days; shorter incubation (<7 days) = worse prognosis [3-4]
- Period of onset: Time from first symptom to first spasm — ≤48 hours indicates poor prognosis [4]
- Symptom progression: Jaw stiffness → neck stiffness → dysphagia → truncal rigidity → generalized spasms (cephalocaudal progression) [2-3]
- Triggers: Spasms worsened by loud noises, bright lights, and physical touch [1-2]
- Vaccination history: Number of primary doses, date of last booster — critical for risk stratification. Tetanus can occur even in partially vaccinated individuals [3]
- Important negatives: Preserved consciousness (lucidity is maintained in tetanus; altered mental status suggests alternative diagnosis) [2]
- In 20–50% of cases, no obvious wound is identified [4]
2. Alarm Features
- Respiratory compromise: Dyspnoea, apnoeic spells, laryngospasm — risk of airway obstruction and respiratory arrest [2-3]
- Rapid symptom evolution: Short incubation period (<7 days) and period of onset (≤48 hours) [4]
- Generalized spasms with opisthotonus [2]
- Autonomic dysfunction: Labile blood pressure, tachycardia alternating with bradycardia, profuse sweating, fever — most feared complication and leading cause of death [2]
- Cardiovascular events: Takotsubo cardiomyopathy (most common cardiac complication), arrhythmia, sudden cardiac arrest — occur days 5–20 of illness [3][5]
- Rhabdomyolysis from prolonged spasms → myoglobinuria → acute kidney injury [2-3]
- Rigid abdomen mimicking acute surgical abdomen — reported cases of unnecessary laparotomy [2-3]
3. Medications
Treatment medications:
- Human tetanus immunoglobulin (hTIG): 500 IU IM (single dose); equine antitoxin if hTIG unavailable (test dose first) [2-3]
- Metronidazole: 500 mg IV q6–8h for 10 days — first-line antibiotic [3]
- Benzodiazepines (diazepam, midazolam): IV for spasm control and sedation — titrate to effect [3]
- Magnesium sulfate: For autonomic dysfunction and adjunctive spasm control [3-4]
- Neuromuscular blocking agents: For refractory spasms in intubated patients [1]
- Labetalol: For sympathetic hyperactivity [3]
- Tetanus toxoid vaccine (Td or Tdap 0.5 mL IM): Administer at different site from hTIG [3]
Medication cautions:
- Penicillin: Non-competitive GABA-A inhibitor — can theoretically potentiate tetanus neurotoxin effects and cause seizures; metronidazole preferred [3]
- Avoid short-acting antihypertensives that may cause rebound hypotension in dysautonomia
- Prophylactic heparin for VTE prevention during prolonged immobility [3]
4. Diet
- NPO initially if significant trismus or dysphagia (aspiration risk) [2]
- Enteral feeding via soft, small-bore nasogastric tube or central venous catheter for nutrition [3]
- High caloric needs due to sustained muscle contractions and hypermetabolic state
- Adequate hydration critical — rhabdomyolysis risk requires aggressive IV fluid resuscitation
5. Review of Systems
- HEENT: Trismus (lockjaw), dysphagia, voice changes, risus sardonicus [2]
- Respiratory: Dyspnoea, apnoeic spells, stridor (laryngospasm) [2-3]
- GI: Abdominal rigidity/pain (can mimic acute abdomen), reduced oral intake [2-3]
- GU: Acute urinary retention (autonomic dysfunction) [2]
- Neuro: Back pain, muscle stiffness, spasms, preserved consciousness [2]
- Autonomic: Sweating, labile blood pressure, tachycardia, fever [2]
6. Collateral History and Family History
- Vaccination records: Verify with primary care or immunization registry — critical for management decisions [3][6]
- Injection drug use history: Subcutaneous ("skin popping") or IM injection of street drugs, particularly heroin, is a major risk factor; outbreaks linked to contaminated heroin [2][4]
- Occupational/environmental exposure: Farming, gardening, soil contact [2]
- Immigration/refugee status: Patients from regions with poor vaccination infrastructure [3]
- Family history is not directly relevant (tetanus is not hereditary and not contagious) [3]
7. Risk Factors
- Undervaccination or unvaccinated status — most important risk factor [1]
- Older age (>65 years): Waning vaccine-induced immunity; born before universal vaccination programs [1-2]
- Injection drug use: Especially subcutaneous injection; contaminated heroin [2][4]
- Diabetes mellitus: Infected extremity ulcers; lower antitetanus antibody levels [2-4]
- Immunosuppression (HIV, immunosuppressive therapy) [3][6]
- Wound type: Puncture wounds, crush injuries, burns, chronic wounds, devitalized tissue [1][3]
- Male sex [2]
- Domestic/gardening injuries [2]
- Post-surgical patients with necrotic infections, septic abortions [3]
- Conflict/disaster zones disrupting vaccination programs [4]
8. Differential Diagnosis
Key distinguishing feature of tetanus: Preserved consciousness with trismus, rigidity, and stimulus-provoked spasms. [2]
9. Past Medical History
- Vaccination history (most critical element) — including childhood series and booster dates [1][3]
- Prior tetanus infection (does not confer immunity — full re-vaccination required) [2]
- Diabetes mellitus, HIV/AIDS, immunosuppressive conditions [3][6]
- Chronic wounds or ulcers
- History of injection drug use [2][4]
- Recent surgery, dental procedures, or trauma [3]
10. Physical Exam
Vital signs:
- Tachycardia (HR >120 bpm in severe disease) [4]
- Labile blood pressure (hypertension alternating with hypotension) [2][4]
- Tachypnoea (RR >30–40) [4]
- Fever (often absent at presentation; if present early, consider alternative diagnosis or superinfection) [2]
Focused exam:
- Trismus (lockjaw): Inability to open mouth — present in 93–98% at admission [2][4]
- Risus sardonicus: Sustained facial muscle spasm producing a grimacing smile [2]
- Opisthotonus: Extreme back hyperextension (late sign, now less common) [2]
- Abdominal rigidity: Board-like abdomen persisting between spasms [2]
- Bilateral hypertonia with superimposed spasms, hyperreflexia, reduced power [2]
- Sensory and cerebellar exam: Normal [2]
- Mental status: Alert and lucid (obtundation = consider NMS or other diagnosis) [2]
- Wound inspection: Identify port of entry; assess for devitalized tissue, foreign bodies [3]
- Dysphagia assessment: Pharyngeal spasm → aspiration risk [2]
11. Lab Studies
Recommended initial labs: [2-3]
- CBC (mild leukocytosis common; neutrophilia = poor prognostic indicator)
- BMP (electrolytes, BUN, creatinine — assess for AKI)
- Creatine kinase (elevated from sustained muscle contraction; monitor for rhabdomyolysis)
- CRP and procalcitonin (moderate CRP elevation expected; marked rise suggests concurrent bacterial infection)
- Urinalysis (haematuria as proxy for myoglobinuria → rhabdomyolysis screening)
- Calcium, magnesium, phosphorus (rule out hypocalcemic tetany; monitor Mg during replacement)
- Liver function tests
- Blood gas analysis
- Serum/urine strychnine assay if poisoning suspected [2]
No confirmatory lab test exists for tetanus — diagnosis is clinical. [1][3] Wound cultures have limited utility (C. tetani is difficult to culture and can be present in normal flora). [3] RT-PCR for C. tetani neurotoxin gene can provide supportive information. [2]
12. Imaging
- Wound CT: May identify foreign bodies or gas locules at wound site [2]
- Neuroimaging (CT/MRI brain): Usually unnecessary; consider only if differential includes stroke, encephalitis, or PRES [2]
- Lumbar puncture: CSF is normal in tetanus; perform only if meningitis is suspected [3]
- Chest X-ray: Baseline and for aspiration pneumonia surveillance
- Echocardiography: If cardiovascular instability — screen for Takotsubo cardiomyopathy (most common cardiac complication, occurring in ~40% of cardiovascular events) [3][5]
13. Special Tests
Severity scoring systems:
- Modified Ablett Classification (most widely used): [4]
- Grade 1 (Mild): Mild trismus, generalized 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, tachycardia/bradycardia)
- Tetanus Severity Score (TSS): Includes age, dyspnoea, time to admission, comorbidities, entry site, BP, HR, temperature — sensitivity 77%, specificity 82%; outperforms Phillips and Dakar scores [3-4]
Spatula test: Previously used (touching posterior pharynx → jaw spasm instead of gag reflex) — no longer recommended due to risk of precipitating laryngospasm. [2]
Heart rate variability (HRV): Emerging tool via wearable ECG devices; inversely related to disease severity and associated with autonomic dysfunction. [7-8]
14. ECG
- Sinus tachycardia: Most common finding, especially in severe disease [2][4]
- Labile heart rate: Alternating tachycardia and bradycardia reflecting autonomic instability [2][4]
- Arrhythmias: Reported in ~19% of cardiovascular events [5]
- ST-segment changes / T-wave inversions: May indicate Takotsubo cardiomyopathy or catecholamine-mediated myocardial injury [3][5]
- Reduced heart rate variability: Correlates with disease severity and autonomic dysfunction [7-8]
- Continuous telemetry is essential — sudden cardiac arrest accounts for ~16% of cardiovascular events [5]
15. Assessment
Tetanus is a clinical diagnosis based on the triad of trismus, muscle rigidity, and stimulus-provoked spasms in a patient with a compatible exposure history and inadequate vaccination. [1-3] There is no confirmatory laboratory test.
Severity stratification using the modified Ablett classification guides ICU management, though early ICU admission should be considered even for mild disease given the risk of rapid deterioration. [2][4]
Typical presentation: Trismus → neck stiffness → dysphagia → truncal rigidity → generalized spasms (cephalocaudal progression) over hours to days. [2-3] Atypical presentations include isolated rigid abdomen (mimicking surgical abdomen), cephalic tetanus (mimicking stroke or Bell's palsy), and localized tetanus confined to an injured limb. [2-3]
Complications to anticipate: Laryngospasm/respiratory failure, autonomic dysfunction (days 5–20), Takotsubo cardiomyopathy, rhabdomyolysis/AKI, nosocomial infections (pneumonia, line infections), VTE from prolonged immobility, and PRES. [2-3][5]
16. Treatment Plan
Initial stabilization (ED):
- Airway: Ensure ventilation; prepare for early intubation if laryngospasm, severe trismus, or respiratory compromise [2-3]
- IV benzodiazepines (diazepam or midazolam) for immediate spasm control [3]
- Quiet, dark environment — minimize stimuli [1][3]
Definitive treatment (ICU):
- hTIG 500 IU IM (single dose) — neutralizes circulating unbound toxin; administer at different site from vaccine [2-3]
- Tetanus toxoid vaccine (Td or Tdap 0.5 mL IM) — regardless of prior vaccination status [3]
- Metronidazole 500 mg IV q6h × 10 days — first-line antibiotic to stop toxin production [3]
- Wound debridement — remove necrotic tissue to eliminate anaerobic environment [3]
- Titrate benzodiazepines for ongoing spasm control and sedation [3]
- Neuromuscular blocking agents (e.g., vecuronium) for refractory spasms in intubated patients [1]
Autonomic dysfunction management:
- Magnesium sulfate IV or labetalol for sympathetic hyperactivity [3]
- Arterial line and invasive hemodynamic monitoring [3]
- Vasopressors (dopamine, norepinephrine) for hypotensive episodes [3]
Supportive care:
- Enteral feeding via NG tube [3]
- DVT prophylaxis with heparin [3]
- Bedside physical therapy [3]
- Taper benzodiazepines over 14–21 days as spasms diminish [3]
Pre-discharge:
- Administer additional dose of Td/Tdap vaccine [3]
- Complete full vaccination series post-recovery [2]
- Physical therapy and psychotherapy referral [3]
17. Disposition
- All suspected tetanus cases require ICU admission — even mild (Ablett Grade 1) disease can rapidly deteriorate [2-3]
- Median hospital stay: 22–30 days; severe cases may require weeks of mechanical ventilation [9-10]
- Mechanical ventilation required in 65–90% of severe cases (Ablett Grade 3–4) [9-10]
- Specialist consultation: Critical care/intensivist, infectious disease, surgery (wound debridement), neurology if diagnostic uncertainty
- Tetanus is not contagious — no isolation precautions required beyond standard precautions
- Mortality: ~13% in tertiary centers with ICU access; significantly higher without mechanical ventilation [4][10]
18. Follow Up / Return Precautions
- Complete the full tetanus vaccination series after recovery (natural infection does not confer immunity) [2]
- Physical rehabilitation: Begin as early as possible once spasms resolve; recovery of inhibitory neurotransmission takes 4–6 weeks [2-3]
- Psychotherapy: Many patients require supportive psychotherapy after prolonged ICU stay [3]
- Expected recovery: Protracted but most patients achieve full functional recovery with sustained ventilatory support [2]
- Return precautions: Seek immediate care for recurrence of muscle stiffness, jaw tightness, difficulty swallowing, or breathing difficulty
- Wound care education: Proper wound cleaning and timely tetanus prophylaxis for future injuries [3]
- Booster schedule: Td/Tdap every 10 years lifelong [3]
References
1. What Is Tetanus?. — Zhou S, Malani P. The Journal of the American Medical Association. 2026.
2. What Is Tetanus?. — Zhou S, Malani P. The Journal of the American Medical Association. 2026.
3. What Is Tetanus?. — Zhou S, Malani P. The Journal of the American Medical Association. 2026.
4. Tetanus: Recognition and Management. — Sudarshan R, Sayo AR, Renner DR, et al. The Lancet. Infectious Diseases. 2025.
5. Tetanus: Recognition and Management. — Sudarshan R, Sayo AR, Renner DR, et al. The Lancet. Infectious Diseases. 2025.
6. Tetanus. — Ergönül Ö, Kolsuz S, Figueroa JP. Lancet. 2026.
7. Tetanus. — Ergönül Ö, Kolsuz S, Figueroa JP. Lancet. 2026.
8. Tetanus. — Yen LM, Thwaites CL. Lancet. 2019.
9. Tetanus. — Yen LM, Thwaites CL. Lancet. 2019.
10. 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.
11. 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.
12. The Survivor: A Clinical Case of Tetanus in a Non-Immunized, Parenteral Drug User, Former Female Convict With HIV and HCV. — Vicente-Alcalde N, Martín-Casquero T, Ruescas-Escolano E, Tuells J. Vaccines. 2020.
13. The Survivor: A Clinical Case of Tetanus in a Non-Immunized, Parenteral Drug User, Former Female Convict With HIV and HCV. — Vicente-Alcalde N, Martín-Casquero T, Ruescas-Escolano E, Tuells J. Vaccines. 2020.
14. Heart Rate Variability as an Indicator of Autonomic Nervous System Disturbance in Tetanus. — Duong HTH, Tadesse GA, Nhat PTH, et al. The American Journal of Tropical Medicine and Hygiene. 2020.
15. Heart Rate Variability as an Indicator of Autonomic Nervous System Disturbance in Tetanus. — Duong HTH, Tadesse GA, Nhat PTH, et al. The American Journal of Tropical Medicine and Hygiene. 2020.
16. Heart Rate Variability Measured From Wearable Devices as a Marker of Disease Severity in Tetanus. — Hai HB, Cattrall JWS, Hao NV, et al. The American Journal of Tropical Medicine and Hygiene. 2024.
17. Heart Rate Variability Measured From Wearable Devices as a Marker of Disease Severity in Tetanus. — Hai HB, Cattrall JWS, Hao NV, et al. The American Journal of Tropical Medicine and Hygiene. 2024.
18. 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.
19. 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.
20. 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.
21. 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.