Link to Problems for Discussion
For a spider bite to be regarded as a definite bite (by a particular type of spider), all of the following must occur:
- Evidence of a bite: clinical effects at the time or soon after the bite, including discomfort or pain;
- Collection of the spider at the time or immediately after the bite;
- Identification of the spider by an expert arachnologist.
Discomfort or pain always occurs with spider bites; their absence goes against the diagnosis. Other important local effects include:
- Fang marks/bleeding are indicative of fang size and so the size of the spider;
- Erythaema/red mark;
- Itchiness (immediate or delayed);
- Swelling/oedema is uncommon.
Over 80% of bites are caused by 6 major families of spiders:
- Orb weavers (Araneidae )
- Huntsmen (Sparassidae )
- White-tail spiders (Lamponidae :Lampona spp.)
- Redback spiders (Latrodectus hasselti) and cupboard spiders (Theridiidae )
- Wolf spiders (Lycosidae )
- Jumping spiders (Salticidae )
The majority of cases of bites involving these spiders result in local pain alone. Systemic effects are rare and mild.