Redback spiders are the most common cause of spider envenomation in Australia, resulting in 5-10,000 bites per year. While the symptoms can be distressing, including inconsolable crying in children and priapism, redback bites are rarely life-threatening. Funnel-web spiders are the most dangerous spiders in Australia; their bites can cause symptoms ranging from local pain and swelling to autonomic effects like sweating and vomiting as well as cardiac or neurological issues. While white-tailed spider bites are often blamed, the venom has not been proven to cause tissue necrosis. Most spider bites result in only localized symptoms, but funnel-web bites require antivenom treatment in the emergency department.

1. Spider
Bites

2. Learning Points
 Understanding of common Aust spiders.
 Recognition of common clinical presentation, &
ED management.
 Highlight some common misinformation about
spider bites.

3. Spider’s
 Australia is home to 1000’s of different spiders.
 The big two are: Red Back and Funnel Web.
 White tail gets blamed for everything.
 Majority of spider bites cause localised symptoms
only.

4. Spider Bites
Can be broken into 3 groups:
1. Big Black spider’s – suspect funnel-web!
2. Redback spiders – look for clinical effect.
3. All other spiders - generally minor effects.

5. Aussie Spiders!

6. Red Back Spider

7. Redback Spider
 RBS most common envenoming is Aust. 5-10 000
each year.
 Clinical features distressing – but not life
threatening.
 RBS live in dry-dark areas.
 Peak bite season January – April.
 The women are the problem!

8. Consider RBS
Children:
 Inconsolable crying
 Acute abdomen
 Priapism

9. Clinical Presentation
Isbister, G. (2006). Spider bite: a current approach to management. Aust Prescriber. 29(6), 156-149.

10. Redback Spider
 Beware of atypical presentations
 Ongoing symptoms weeks-months consider
psych!

11. Emergency Department
Management.
Pre-hospital:
 Reassure, ICE-pack, simple analgesia.
In ED:
2 approaches:
 Provide analgesia/antimetics – if Sx resolve D/C.
 Antivenom: 2 x 500units of CSL RBS iv over 30min. (monitor for
reactions).
 Rpt if Sx not improved after 2 hours.
Antivenom effectiveness currently being studied. (RAVE2)

12. Funnel-web spider

13. Funnel-web spider
 Most dangerous spider in Australia.
 Comprise 40 species in 2 genera.
 Big black spider bite = FWS bite until patient has
been observed for 4/24.
 Found in QLD and NSW.
 The males are the problem

14. Clinical Presentation
 Hx of being bitten by big black spider with fangs.
Localised:
 Severe bite site pain with fang marks.
 Local erythema & swelling are NOT present.
Systemic:
 General: agitation, vomiting, headache, abdo pain.
 Autonomic: sweating, salivation, piloerection, lacrimation.
 Cardio: HT, tachycardia, hypotension, bradycardia, APO.
 Neuro: muscular fasciculation's or spasm, coma.
Children:
 Sudden severe illness with inconsolable crying, salivation, vomiting or collapse.

15. Emergency Department
Management.
Pre-hospital:
 Apply PIB- T/F to hospital that has antivenom.
In ED:
 Manage in Resus area – full monitoring!
 Look out for– resp failure, hypo/hypertension, APO, &
coma.
 Antivenom: give 2 x 125units of CSL Funnel-web Spider
Antivenom – RPT if needed.
 Cardiac arrest: Give 4 ampoules undiluted antivenom.

16. White Tail Spider

17. White-tailed spider
 Common spider found around Australia.
 Often blamed for causing necrotic arachnidism.
 Venom has shown NO definitive toxic
components.

18. Clinical Presentation
Localised:
 Painful bite
3 local reaction can occur:
1. Severe local pain <2 hours duration
2. Local pain & a red mark lasting <24hours.
3. Persistent & painful red lesion, which does not break
down or ulcerate – may last 5-12 days.
 Other features of nausea, malaise, vomiting &
headache may occur.
 Delayed puritus can occur in up to 20% of cases.

19. Differential Diagnosis!
 Infection
 Diabetic ulcer
 Pyoderma gangrenosum
 Squamous cell carcinoma
 Erythema nodosum
 Chemical burn
 Localised vasculitis
 Factitious injury
 Traumatic.

20. Emergency Department
Management.
 Look for other causes and treat them.
 Diabetic ulcers
 Infections (MRSA)
 Simple analgesia/antiemetic if required.
 Provide reassurance and education!

21. Questions

22. Take Home Points
 Patient’s with signs of envenoming shouldn’t be
D/C at night.
 Antivenom carries risk and reactions.
 Consider analgesia first in RBS.
 Look for other cause before blaming the white
tail!

23. Thank-you