Tick Bite Management

Ticks may cause many types of reactions, including local and systemic infections, allergy, paralysis, autoimmune disease, post-infection fatigue and Australian multisystem disorder. Three types of ticks in Australia are known to transmit bacterial infection (see table below). The burden of tick-related illness is difficult to quantify as only Q-fever is notifiable. There is no evidence that Australian ticks transmit viral illnesses as they do in other parts of the world.

Ticks causing bacterial infections in Australia

Table: Australian tick species which transmit bacterial infections

If working or walking around tick habitats, use insect repellent containing DEET or Picaridin to prevent bites. Bites are initially painless and normally go unnoticed until the tick has become engorged 2 or more days after attaching. They can walk on the body for 2 - 4 hours before attaching so clothing should be washed in hot water and preferably dried in a dryer to kill any remaining ticks in clothing. They usually bite in moist or vascular sites - the scalp or flexor areas.

Remove ticks carefully with fine-tipped forceps by gripping the tick at is mouthpiece and pulling it straight out of the host’s skin. Avoid squeezing or pulling the tick by the abdomen, increasing the risk of injecting more toxin or breaking the tick and leaving remnants of the head or mouth in the host’s skin. There is evidence that killing ticks in situ (eg. with dimethylether (Wart-off) or aerosol insect repellent containing pyrethrin or a pyrethroid) may reduce the risk of systemic reactions and anaphylaxis.

Local reactions are the most common sequelae of tick bite and resolve without treatment. They may cause local erythema and swelling directly from tick saliva; an urticarial rash; or “scrub itch” from nymph infestation. Antihistamine can provide symptomatic relief for swelling and itch. Use permethrin creams (eg. Lyclear) on nymph infestation. Systemic reactions have occurred causing anaphylaxis and death. This is rare. The longer the tick has been attached to the host increases the risk of systemic illness.

The Australian paralysis tick injects neurotoxins (holocyclotoxins) when it bites. It can cause ataxia and an ascending flaccid paralysis that resembles Guillain-Barre syndrome. Cranial nerve palsies may occur causing opthalmoplegia or facial paralysis similar to Bell’s Palsy. Symptoms may progress after removal of the tick for 24-48 hours. Small animals and family pets are most vulnerable to tick paralysis. A human death from tick paralysis has not occurred for decades and anti-venom is no longer available for human use. Admission to hospital for serial neurological examination is required. Severe cases will require advanced life support including intubation and ventilation.

Rickettsial infection (tick typhus) presents as fever, lethargy, anorexia, arthralgia, generalised rash and a plaque with eschar at the original tick bite site. Symptoms occur 2-14 days after the tick bite and requires prompt treatment with doxycycline 100 mg (child: 2.2 mg/kg up to 100 mg), twice daily for 7 days.

Further Resources and References

Taylor, Benjamin & Ratchford, Andrew & van nunen, Sheryl & Burns, Brian. (2019). Tick killing in situ before removal to prevent allergic and anaphylactic reactions in humans: a cross-sectional study. 10.5415/apallergy.2019.9.e15.

Department of Medical Entomology, University of Sydney. Ticks. http://medent.usyd.edu.au/fact/ticks.htm#treat

Graves, S. R. and Stenos, J. (2017)Tick-borne infectious diseases in Australia.Med J Aust 2017; 206 (7): . || doi: 10.5694/mja17.00090 https://www.mja.com.au.acs.hcn.com.au/journal/2017/206/7/tick-borne-infectious-diseases-australia

Debilitating Symptom Complexes Attributed to Ticks (DSCATT)