Can spider venom cause prolonged symptomatology, including burning pain, weakness, and paresthesia, in a patient with a history of spider bite?

Spider Bite with Progressive Neurological Symptoms: Evaluation and Management

Spider venom does not typically cause the prolonged and progressive neurological symptoms described in this patient, and an alternative neurological diagnosis should be strongly considered. 1

Clinical Assessment of the Presentation

The patient's symptoms are concerning for several reasons:

• Initial bite in the axilla with burning pain
• Progressive spread of symptoms from axilla to shoulder, neck, and contralateral chest
• Development of weakness in the right arm and leg
• Duration of symptoms (three weeks and worsening)

These features are not consistent with known spider envenomations in North America for the following reasons:

Spider Envenomation Patterns in North America

• Black widow spider (Latrodectus) envenomation:

  • Causes severe crampy pain, muscle rigidity, diaphoresis, and hypertension
  • May cause a rash around the bite site but does not cause local tissue injury
  • Symptoms typically peak within hours and resolve within 24-72 hours with or without treatment 1, 2
  • Does not cause progressive neurological deficits over weeks 3

• Brown recluse spider (Loxosceles) envenomation:

  • Causes painful ulcerated wounds that progress over days to weeks
  • May be associated with hemolysis and rhabdomyolysis
  • Does not cause progressive neurological symptoms like weakness in contralateral limbs 1

Differential Diagnosis

The patient's presentation suggests an alternative neurological diagnosis:

1. Cervical radiculopathy or myelopathy - The progression from shoulder to neck with ipsilateral arm and leg weakness suggests a cervical spine pathology

2. Brachial plexopathy - Initial axillary involvement with progression to arm weakness

3. Multiple sclerosis - Progressive neurological symptoms over weeks

4. Peripheral neuropathy - Progressive sensory and motor symptoms

5. Thoracic outlet syndrome - Compression of neurovascular structures in the axilla/shoulder region

Recommended Management

1. Urgent neurological evaluation including:

   • MRI of the cervical spine and brachial plexus
   • Electromyography and nerve conduction studies
   • Complete neurological examination

2. Discontinue spider bite treatment approach as the symptoms are not consistent with spider envenomation 1, 4

3. Pain management with appropriate analgesics while awaiting definitive diagnosis

Important Considerations

• Old World tarantulas (not native to North America) can cause muscle spasms that persist for days, but these do not typically cause progressive weakness or spread to contralateral limbs 5

• Neurological effects from venomous bites typically manifest within hours to days, not progressively over weeks 4

• The pattern of symptom spread (axilla → shoulder → neck → contralateral chest) with ipsilateral limb weakness strongly suggests a neurological disorder rather than envenomation 4

Conclusion

The patient's clinical presentation is not consistent with any known spider envenomation in North America. The progressive nature and distribution of symptoms over three weeks strongly suggest a neurological disorder requiring prompt evaluation. Focusing on spider envenomation as the cause may delay appropriate diagnosis and treatment of a potentially serious neurological condition.