What is the treatment for a spider bite?

Treatment for Spider Bites

The treatment for spider bites depends on the type of spider, with black widow spider bites requiring pain management and supportive care, while brown recluse spider bites may require wound care and potentially more advanced interventions. 1, 2

Initial Assessment and First Aid

• For all spider bites, cleanse the area with soap and water and let it dry before applying any topical treatments 3
• Seek medical care immediately if systemic symptoms develop, such as difficulty breathing, muscle rigidity, dizziness, or confusion 1
• Apply ice to the bite site for local pain relief 1
• Over-the-counter acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) are recommended for pain management 1
• Topical lidocaine can be applied if the skin is intact for additional pain relief 1
• Calamine lotion may be applied to the affected area as needed for comfort in patients 2 years and older 3

Black Widow Spider Bites

• Black widow bites typically cause severe crampy pain, muscle rigidity, diaphoresis, and hypertension with minimal local tissue injury 1
• Treatment focuses on pain control, with options including:
  • Over-the-counter analgesics for mild pain 1
  • Muscle relaxants may be needed for severe muscle cramping 2, 4
  • Calcium gluconate is sometimes used to manage neuromuscular symptoms 2, 4
  • Specific antivenin is available but generally reserved for severe cases 2
• The very young, very old, and those with underlying health conditions require closer monitoring due to higher risk for severe reactions 1

Brown Recluse Spider Bites

• Brown recluse bites can cause dermonecrosis within 72-96 hours of the bite 2
• First-line treatment includes:
  • Rest and ice compresses 2
  • Antibiotics if signs of infection develop 2
  • Dapsone may be effective for severe dermic lesions, but should be used cautiously due to potential toxicity 2, 5
• For necrotic wounds:
  • Early intervention with curettage of the subcutaneous tissue in the necrotic area may prevent further necrosis 6
  • Surgical debridement is typically delayed for several weeks 2
  • For non-healing wounds, hyperbaric oxygen therapy can be beneficial even months after the bite 7

Common Pitfalls to Avoid

• Delaying medical care when systemic symptoms are present 1
• Underestimating the severity of envenomation based solely on local findings at the bite site 1
• Assuming antibiotics are needed for swelling around the bite site when it's typically caused by mediator release, not infection 8
• Immediate surgical intervention for brown recluse bites can worsen outcomes; surgery should typically be delayed 2
• Using systemic corticosteroids without clear indication - they may be helpful in rare systemic loxoscelism with hemolysis but have limited evidence for routine use 2, 8