What is the treatment for a spider bite?

Treatment for Spider Bites

For spider bites, thoroughly irrigate the wound with copious amounts of clean water and apply a clean occlusive dressing with antibiotic ointment to prevent infection. 1

Initial Assessment and First Aid

• Thoroughly clean the bite wound with a large volume of warm or room temperature potable water to remove any foreign matter 1
• Cover the wound with antibiotic ointment or cream and a clean occlusive dressing to improve healing and reduce infection risk 1
• Apply ice to the bite site for pain relief, placing a thin barrier between the ice and skin to prevent tissue damage 2
• Remove rings and other constricting objects from the bitten extremity as swelling may occur 2
• Do not apply suction to the bite site as this is ineffective and potentially harmful 2
• Do not apply tourniquets or pressure immobilization bandages as these may worsen tissue injury 2

Treatment Based on Spider Type

Brown Recluse Spider Bites

• Brown recluse bites can cause dermonecrosis within 72-96 hours 3
• Treatment includes:
  • Rest and ice compresses 3
  • Over-the-counter pain medications (acetaminophen and NSAIDs) 2
  • Antibiotics to prevent secondary infection 3
  • Dapsone may be considered for severe cases 3, 4
  • Delay surgical intervention for several weeks 3
• For systemic loxoscelism (rare but serious with minimal skin changes but massive hemolysis), systemic corticosteroids may be helpful 3

Black Widow Spider Bites

• Black widow bites primarily produce muscle cramping, pain, and neuromuscular symptoms rather than marked skin changes 3
• Treatment includes:
  • Pain control medications 3
  • Muscle relaxants 3, 4
  • Calcium gluconate for symptom management 3, 4
  • Specific antivenin is available for severe cases but rarely needed 3, 5

When to Seek Medical Attention

• Seek immediate medical care if systemic symptoms develop, including: 2
  • Difficulty breathing
  • Muscle rigidity
  • Dizziness or confusion
  • Signs of anaphylaxis
• Medical attention is also warranted if: 6
  • Pain extends beyond the bite site or becomes severe
  • Pain is not controlled by over-the-counter medications
  • An open wound develops
  • Signs of infection appear (progressive erythema, purulent discharge, fever)

Special Considerations

• For non-healing wounds from brown spider bites, hyperbaric oxygen therapy (HBOT) may be beneficial even months after the bite 7
• Large local reactions may benefit from oral antihistamines and in severe cases a short course of oral corticosteroids 1
• Antibiotics are usually not necessary for large local reactions unless signs of secondary infection develop 1

Common Pitfalls to Avoid

• Assuming all swelling indicates infection - most swelling is due to inflammatory response, not infection 6
• Delaying epinephrine administration in cases of anaphylaxis 1
• Applying tourniquets or pressure immobilization bandages which may worsen tissue injury 2
• Unnecessary use of antibiotics for uncomplicated bites 1