White-tailed Spiders are fund throughout Australia and wrongfully been accused of causing necrotic lesions on the skin. We now how evidence that this is not the case and a painful bite with red mark is the typical presentation.
Typical symptoms include:
- A painful bite with a red mark – can last up to 12 days
- Non-specific features of envenoming can include nausea, vomiting, headache and malaise
- Delayed pruritus occurs in 20%
1. Reassure the patient, apply an ice pack and give simple analgesia. A hospital admission is not required.
- Only required to establish an alternative diagnosis, this might include swabs or skin biopsies.
- If a necrotic cutaneous lesion is present then the following other differentials need to be considered:
- Infections (staphylococcal, streptococcal, herpes simplex, herpes zoster, gonococcal, mycobacterial, fungal)
- Pyoderma gengrenosum
- Squamous cell carcinoma
- Erythema nodosum
- Chemical burn
- Lymphomatous papulosis
- Localised vasculitis
- Factitious injury
- None available
- Patients can all be discharged with appropriate follow-up by a primary care provider, particularly if a necrotic lesion is present.
References and Additional Resources:
- Chris Nickson – Spiders and Stingers – SMACC podcast
- Isbister GK, Gray MR. White-tailed spider bite: a prospective series of 130 definite bites by the Lampona species. Medical Journal of Australia 2003; 179:199-202
- Swanson DL, Vetter RS. Bites of the brown recluse spiders and suspected necrotic arachnids. New England Journal of Medicine 2005; 352:700-707