Learning Points Understanding of common Aust spiders. Recognition of common clinical presentation, &ED management. Highlight some common misinformation aboutspider bites.
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 symptomsonly.
Spider BitesCan 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.
Redback Spider RBS most common envenoming is Aust. 5-10 000each year. Clinical features distressing – but not lifethreatening. RBS live in dry-dark areas. Peak bite season January – April. The women are the problem!
Emergency DepartmentManagement.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 forreactions). Rpt if Sx not improved after 2 hours.Antivenom effectiveness currently being studied. (RAVE2)
Funnel-web spider Most dangerous spider in Australia. Comprise 40 species in 2 genera. Big black spider bite = FWS bite until patient hasbeen observed for 4/24. Found in QLD and NSW. The males are the problem
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 fasciculations or spasm, coma.Children: Sudden severe illness with inconsolable crying, salivation, vomiting or collapse.
Emergency DepartmentManagement.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 SpiderAntivenom – RPT if needed. Cardiac arrest: Give 4 ampoules undiluted antivenom.
White-tailed spider Common spider found around Australia. Often blamed for causing necrotic arachnidism. Venom has shown NO definitive toxiccomponents.
Clinical PresentationLocalised: Painful bite3 local reaction can occur:1. Severe local pain <2 hours duration2. Local pain & a red mark lasting <24hours.3. Persistent & painful red lesion, which does not breakdown 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.
Take Home Points Patient’s with signs of envenoming shouldn’t beD/C at night. Antivenom carries risk and reactions. Consider analgesia first in RBS. Look for other cause before blaming the whitetail!