Skip to content
My WebMD Sign In, Sign Up

Brain & Nervous System Health Center

Font Size

Toxin From Tick Bite Paralyses Girl, Stumps Physicians


The tick found was not the kind that causes Lyme disease, but does carry Rocky Mountain Spotted Fever. If the tick is pregnant and feeding on a person, it produces an extremely potent toxin that can cause paralysis in humans and animals. Within 17 days, the tick produced 200 eggs. Both the tick and the eggs later died in Felz's office.

For her part, the child recovered quite rapidly. "We took the tick off about 3:18 p.m., and I was on call that night so I was checking her," Smith says. "You could watch her improve. It was just amazing to watch. Her grandmother and her mother, they were just so thankful. Here she was almost on a ventilator. It was really dramatic."

The child was hospitalized another 32 hours after the tick was removed, and subsequent neurological tests have been normal. Had the tick not been removed, it is likely that the paralysis that had first gripped her legs and then her arms would have continued ascending up her body, engulfing her lungs and making a ventilator necessary. The plasmapheresis, had it been performed, and any other aggressive interventions, would have been of no value.

Ultimately, the tick would have finished feeding and fallen off on its own, Felz says, but in cases where the person is not placed on a ventilator, death may occur before that happens. There have been reports of ticks being found during autopsies of patients who died of unexplained paralysis.

"A diagnosis of Guillain-Barre syndrome should not be accepted until a careful search has excluded the possibility that a tick is present. One may literally have to comb for the evidence," the authors write.

In an accompanying editorial, Herbert H. Schaumburg, MD, and Steven Herskovitz, MD, with the Albert Einstein School of Medicine in New York, recount their own recent instance of mistaken diagnosis, in which a technician applying electrodes for a EEG found a tick that had gone undetected in a child experiencing changes in consciousness.

These authors point out that botulism can also cause paralysis. "The report by Felz and colleagues is a lesson the perils of hasty diagnosis in children with ... paralysis," they write.

Vital Information:

  • A common wood tick that carries Rocky Mountain Spotted Fever can cause paralysis, and even death, in patients if it is not removed promptly.
  • If the tick is pregnant and feeding on a person, it produces a potent toxin that causes paralysis.
  • In a recent case report, a young girl recovered rapidly once doctors realized that a tick was causing her symptoms and removed it.

Today on WebMD

3d scan of fractured skull
human brain waves
brain maze
senior man
brain research briefing
Vaccine and needle
mans hands on laptop keyboard
brain illustration stroke
most common stroke symptoms
Parkinsons Disease Medications