Acute tetanus

Background

1. C. tetani spores enter skin through wound, make tetanospasmin toxin
   1. Lacs, abrasions, puncture wounds
   2. Preferentially binds GABA and glycinergic neurons and blocks presynaptic release
      1. Motor neurons undergo sustained excitatory discharge
2. Spores found in soil and human feces
3. 2001-2008 in US, 233 cases, 26 deaths
4. Mortality as high as 45%
5. Incubation is 2 to 56d
6. If the pt survives, no residual sequealae

Types

Neonatal

1. from umbilical stump infection. Usually protected by passive maternal Abs
2. sx- poor suck, irritability, crying, grimacing
3. usually with in 10 d of birth

Local

1. rigidity of muscles near wound- may progress to generalized

Generalized

1. most common form
2. pts are conscious and alert
3. hypersympathetic state c sweating, HTN, tachycardia, fever

Cephalic

1. follow injuries to head or otitis media
2. get CN dysfunction- usually CN 7

Diagnosis

1. Progressive symptoms
   1. Alert and able to communicate
   2. Trismus - lockjaw (50%-75% of patients)
   3. Sardonic smile (risus sardonicus) - other facial muscles become involved
   4. Minor stimuli such as touch or noise start tetanic contractions
   5. Abd, back, diff swallowing
   6. Long bone fractures, tendon rupture
   7. Opisthotonus - contractures that resemble decorticate posturing
2. DX = clinical

Differential Diagnosis

Jaw Spasms

• Acute tetanus
• Akathisia
• Conversion disorder
• Drug toxicity (anticholinergic, phenytoin, valproate, carbamazepine)
• Dystonic reaction
• Electrolyte abnormality
  • Hypocalcemic tetany
  • Magnesium
• Mandible dislocation
• Meningitis
• Peritonsillar abscess
• Rabies
• Seizure
• Strychnine poisoning
• Stroke
• Temporomandibular disorder
• Torticollis

Treatment

• Before wound debridement, apply immunoglobulin (TIG) directly into the wound and IM
  • Dose: 3000-6000 units IM with adequate mL to wound
  • Des not reverse toxin already fixed to CNS. Binds circulating toxin

Supportive Care

• Place patient in a quite room
• Provide sedation with Benzodiazepines or phenobarbital

Antibiotics

• Metronidazole 500mg IV (7.5mg/kg) q6hrs OR
• Clindamycin 600mg IV (7.5mg/kg) q6hrs

Penicillin

• Although once the drug of choice it is now no longer recommended since it may potentiate the effect of tetanus toxin by inhibiting the GABA receptors

See Also

• Tetanus (Prophylaxis)
• Clostridium