Spiders

Question 1

Differential for a spider bite site:

Answer 1

Cellulitis
IVDU
Pyoderma gangrenosum
Vasculitis
Arterial/ venous ulcer

Bite from another animal

Question 2

Answer 2

WHITE TAILED

Debunked: doesn’t cause nec fasc
Minor local symptoms only

Question 3

Answer 3

REDBACK.

Ubiquitous
Urban

Symptoms over 1 hour:
- Pain +++ —> radiates trunk, nodes
- LOCAL SWEATING (often distant too)
- Piloerection
Systemic in 30% sympathetic, N&V, malaise, headache, priapism etc

Symptoms last days

MANAGEMENT
Ice/compress
Analgesia (often refractory + even to IV)
2 vials redback antivenom IM or IV FOR PAIN

Question 4

Answer 4

FUNNEL WEB.

Whole East Coast of Aus
Only 6 bad ones: Southern NSW to Southern QLD
On ground

Venom keeps Na channels open

Painful bite
Severe within 30mins:
- Paraesthesias: perioral, local, distal
- Fasciculations
- Nonspecific: nausea, abdo pain etc.
- Agitation/ anxiety
- Autonomic storm: PNS and/or SNS features
Eg. Saliva/sweat/tears/brady OR tachy/Mydriasis etc.
—> Coma, APO.

MANAGEMENT
Pressure bandage
Immobilisation
Usual ABCD
2 vials FWS antivenom IV. Repeat 30min PRN.
Atropine/metoprolol (dep if PNS/SNS person) whilst awaiting antivenom

Question 5

Dose of spider antivenom in children?

Answer 5

As for all antivenom, same dose as for adult
- needs to neutralise same venom load, regardless of body size