General considerations

In most cases of snake bite, insufficient venom is injected to cause any effects. If effects occur, they vary depending on the snake group. The geographical distributions and effects of clinically important terrestrial snake groups endemic to Australia are outlined in Envenoming syndromes and geographical distributions of clinically important Australian terrestrial snakes.

Systemic envenoming is characterised by the following effects (see also Evidence of systemic envenoming from snake bite):

snake venom coagulopathy
neurotoxicity
myotoxicity
thrombotic microangiopathy
acute kidney injury
early cardiovascular collapse (eg hypotension, cardiac arrest, unconsciousness, seizures); death due to snake bite is most commonly associated with cardiovascular collapse and cardiac arrest.

Patients with systemic envenoming may also experience nonspecific systemic symptoms, such as nausea, vomiting, headache, abdominal pain, diarrhoea and sweating.

Compared to snakes in other countries, which cause significant local injury at the bite site, Australian snakes seldom cause local effects, except in significant systemic envenoming. The whip snake, although not clinically important, is a common snake in Australia that occasionally causes painful local swelling at the bite site that may be mistaken for inflammation or infection. Black snake (Pseudechis species) and tiger snake (Notechis species) bites can also cause painful local swelling and, infrequently, tissue injury.

Table 1. Envenoming syndromes and geographical distributions of clinically important Australian terrestrial snakes
Snake group or type	Features of envenoming syndrome	Geographical distribution
*brown snake (Pseudonaja* species)**	VICC cardiovascular collapse acute kidney injury thrombotic microangiopathy	mainland Australia
*tiger snake (Notechis* species)**	VICC myotoxicity neurotoxicity acute kidney injury thrombotic microangiopathy nonspecific systemic symptoms cardiovascular collapse	southern Australia, including Tasmania and southern Western Australia
*rough-scaled snake (Tropidechis carinatus)*	VICC myotoxicity neurotoxicity acute kidney injury thrombotic microangiopathy nonspecific systemic symptoms	eastern Australia
Hoplocephalus species (broad-headed, pale-headed and Stephen’s banded snake)	VICC acute kidney injury thrombotic microangiopathy	eastern Australia
*red-bellied black snake (Pseudechis porphyriacus)*	nonspecific systemic symptoms anticoagulant coagulopathy myotoxicity	eastern Australia
*death adder (Acanthophis* species)**	neurotoxicity nonspecific systemic symptoms	mainland Australia, but not Victoria
*taipan (Oxyuranus* species)**	VICC neurotoxicity cardiovascular collapse myotoxicity acute kidney injury thrombotic microangiopathy	northern Australia, mainly far north Queensland
*mulga snake (Pseudechis australis) [NB1]*	myotoxicity nonspecific systemic symptoms anticoagulant coagulopathy	mainland Australia, but not eastern seaboard
Note: VICC = venom-induced consumption coagulopathy NB1: Bites by Collett’s snake (Pseudechis colletti) cause similar effects to the mulga snake and are treated in the same way, but almost exclusively occur in snake handlers.