Tick paralysis

• Causes, incidence, and risk factors

  Hard- and soft-bodied female ticks are believed to make a poison that can cause paralysis in children. Ticks attach to the skin to feed on blood. It is during this feeding process that the toxin enters the bloodstream.

  The paralysis is ascending -- that means it starts in the lower body and moves up. It is similar to that seen in Guillain-Barre syndrome and opposite that seen in botulism and paralytic shellfish poisoning.

• Symptoms

  Children with tick paralysis develop an unsteady gait (ataxia) followed several days later by weakness in the lower legs that gradually moves up to involve the upper limbs.

  Paralysis may cause breathing difficulties, which may require the use of a breathing machine.

  The child may also have mild, flu-like symptoms (muscle aches, tiredness).

• Signs and tests

  The person will have been exposed to ticks in some way. For example, he or she may have been on a recent camping trip, live in a tick-infested area, or have dogs or other animals that can pick up ticks. Often the tick is found only after thoroughly searching the person's hair.

  Finding a tick embedded in the skin and noting above symptoms confirms the diagnosis. No other testing is required.

• Treatment

  Removing the tick removes the source of the neurotoxin. Recovery is rapid following the removal of the tick.

• Expectations (prognosis)

  Full recovery is expected following the removal of the tick.

• Complications
  • Respiratory failure
• Calling your health care provider

  If your child suddenly becomes unsteady or weak, have the child examined promptly. Breathing difficulties require emergency care.

• Prevention

  Use insect repellents and protective clothing when out in tick-infested areas. Carefully check the skin after being outside and remove any ticks.

  As a rule, if children are discovered to have ticks, it is a good idea to write the information down and keep it for several months. Many tick-borne diseases do not show symptoms immediately, and the incident may be forgotten by the time a child becomes sick with a tick-borne disease.

• References

  Bolgiano EB, Sexton J. Tick-borne illnesses. In: Marx J, ed. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 6th ed. St Philadelphia, Pa: Mosby Elsevier; 2006:chap 132.

Review Date: 5/12/2009

Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.