Tick paralysis

Definition

An acute, ascending flaccid paralysis caused by neurotoxins in the saliva of certain tick species, typically developing during prolonged engorgement (usually 4–7 days) and rapidly reversing upon tick removal. The condition is clinically indistinguishable from Guillain-Barré syndrome and can progress to respiratory failure if the tick remains attached. Unlike infectious tick-borne diseases, tick paralysis is a toxemia with no pathogen involved.

Etymology

From English 'tick' (the arachnid parasite) + 'paralysis' (loss of voluntary muscle function), describing the symptomatic outcome of envenomation.

Example

In Australia, Ixodes holocyclus (paralysis tick) causes thousands of domestic animal deaths annually; in humans, a single female Dermacentor andersoni (Rocky Mountain wood tick) attached behind the ear can produce life-threatening respiratory paralysis within days.

Synonyms

• tick toxicosis
• tick-bite paralysis

Related Terms

• tick-borne disease
• Neurotoxin
• ascending paralysis
• Ixodidae
• engorgement
• toxemia
• Guillain-Barré syndrome

Usage Notes

Distinguished from infectious tick-borne illnesses (e.g., Lyme disease, Rocky Mountain spotted fever) by its non-infectious, toxin-mediated etiology and rapid resolution after tick removal. Diagnosis is clinical; tick identification is helpful but not required for treatment. In veterinary contexts, 'tick toxicosis' is often preferred. The condition is underreported in humans because presentation mimics other neuromuscular disorders and ticks may be hidden in scalp or body folds.