What is the treatment for a brown recluse spider bite?

Treatment for Brown Recluse Spider Bites

The definitive treatment for brown recluse spider bites includes thorough wound irrigation with warm water, application of clean dressings, pain management with over-the-counter medications, and seeking medical attention for severe or systemic symptoms. 1

Initial Assessment and First Aid

• Thoroughly irrigate the bite wound with a large volume of warm or room temperature potable water until there is no foreign matter in the wound 1
• Apply antibiotic ointment and cover with a clean occlusive dressing to improve healing and reduce infection risk 1
• Apply ice with a clean barrier between ice and skin for local pain relief 1
• Remove rings and other constricting objects from the bitten extremity, as swelling may occur 1
• Update tetanus status as needed 2

When to Seek Medical Care

• Seek medical attention immediately if systemic symptoms develop, such as:
  • Difficulty breathing
  • Muscle rigidity
  • Dizziness
  • Confusion 1, 3
• Also seek medical care if:
  • 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 1

Treatment Options Based on Severity

For Local Symptoms Only

• Over-the-counter acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) for pain management 1, 3
• Topical lidocaine (5%) can be applied if the skin is intact for pain relief 3
• Most patients with local symptoms only will recover completely within 24-48 hours 1

For Necrotic Wounds (Necrotic Arachnidism)

• Surgical excision is indicated only for lesions that have stabilized and are no longer enlarging 2
• Delaying surgery for several weeks is recommended as premature intervention may worsen outcomes 4
• Topical nitroglycerin has been suggested to potentially decrease the enlargement of necrotic skin ulcers, though evidence of effectiveness is limited 2, 5

For Systemic Symptoms (Loxoscelism)

• Hospitalization is required for patients who develop systemic symptoms 2
• Systemic corticosteroids may be beneficial in cases with:
  • Severe skin lesions
  • Systemic loxoscelism (with minimal skin changes but massive hemolysis)
  • Small children 2, 4

Special Considerations

• Dapsone has been used for necrotic arachnidism in adults, but:
  • Patients must be screened for glucose-6-phosphate dehydrogenase deficiency before use 2
  • Evidence suggests it may be associated with slower healing and increased scarring 5
  • Should be reserved only for severe cases due to potential toxic effects 6
• Hyperbaric oxygen therapy has been used in some severe cases with hemolysis and extensive necrotic wounds 7

Common Pitfalls to Avoid

• Do not apply suction to the bite site as this is ineffective and potentially harmful 1
• Avoid applying tourniquets or pressure immobilization bandages as these may worsen tissue injury 1
• Do not assume antibiotics are needed for swelling around the bite site, as swelling is typically caused by mediator release, not infection 1
• Avoid premature surgical intervention of necrotic wounds 4

Follow-up Care

• Continue pain management with over-the-counter medications as needed for several days 1
• Monitor for signs of secondary infection at the bite site 1
• Be aware that healing time for more severe bites averages around 17 days, with approximately 21% of cases resulting in permanent scarring 5