II. Epidemiology

  1. Northwest United States
  2. Peak onset in spring: April to June

III. Pathophysiology

  1. Neurotoxin secretion during tick attachment or feeding via Saliva (non-infectious)
  2. Occurs with Female ticks of several species
    1. Dermacentor (e.g. American Dog Tick, Rocky Mountain Wood Tick)
    2. Amblyomma (e.g. Gulf Coast Tick)
    3. Ixodes

IV. Findings

  1. Acute ascending Flaccid Paralysis
    1. Onset 2-6 days after Tick Bite
  2. Neurologic progression
    1. Difficulty walking or standing
    2. Ataxia
    3. Absent Deep Tendon Reflexes
    4. Drooling
    5. Tachypnea
  3. Girls under age 10 years old may have unique presentations
    1. Ataxia
    2. Weakness without sensory loss
    3. Graham (2011) Pediatr Emerg Care 27(2): 141-7 [PubMed]

V. Differential Diagnosis

  1. Guillain-Barre Syndrome
    1. Tick Paralysis progresses more rapidly than Guillain-Barre Syndrome

VI. Management

  1. Removal of tick is curative (typically within 24 hours)

VIII. Prognosis: Unrecognized infection (tick not removed)

  1. Progresses to Respiratory Failure and death

IX. References

  1. Green and Millsap (2016) Crit Dec Emerg Med 30(1): 4
  2. Pensa and Werner in Swadron (2022) EM:Rap 22(5): 8-12

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