White-tailed Spider

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.

  • Not required
Risk Assessment

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%

Supportive Care

  • 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.
Differential Diagnosis:
  • 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
  • Traumatic
  • 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:

Additional Resources:


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Dr Neil Long BMBS FACEM FRCEM FRCPC. Emergency Physician at Kelowna hospital, British Columbia. Loves the misery of alpine climbing and working in austere environments (namely tertiary trauma centres). Supporter of FOAMed, lifelong education and trying to find that elusive peak performance.

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