What is the recommended treatment for a brown recluse spider bite?

Treatment for Brown Recluse Spider Bite

The primary treatment for brown recluse spider bites is supportive care with rest, ice compresses, wound irrigation, pain control with over-the-counter analgesics, and delayed surgical debridement only if significant necrosis develops—antibiotics are NOT routinely indicated unless signs of secondary bacterial infection appear. 1

Initial Wound Care and Pain Management

• Thoroughly irrigate the bite wound with copious amounts of warm or room temperature water until no foreign matter remains in the wound. 2, 1
• Apply ice to the bite site with a clean barrier between ice and skin for local pain relief. 2, 1
• Apply antibiotic ointment and cover with a clean occlusive dressing to improve healing and reduce infection risk. 2, 1
• Remove rings and other constricting objects from the affected extremity immediately, as swelling may occur. 2, 1
• Elevate the affected extremity to reduce swelling and accelerate healing. 1

Pain Control

• Use over-the-counter acetaminophen or NSAIDs for pain management. 1
• Topical lidocaine 5% can be applied if the skin is intact for additional pain relief. 1
• Continue pain management with over-the-counter medications as needed for several days. 2, 1

Critical Pitfall: Avoid Routine Antibiotics

Swelling in the first 24-48 hours is caused by venom-induced inflammatory mediator release, NOT infection, and does not require antibiotic therapy. 2, 1

• Universal prophylaxis with antibiotics is not recommended for bite wounds. 1
• Only prescribe antibiotics if clear signs of secondary bacterial infection develop: progressive erythema extending beyond the initial bite site, purulent discharge, or systemic signs like fever or elevated white blood cell count. 1
• For confirmed secondary bacterial infection, first-line oral therapy includes trimethoprim-sulfamethoxazole or doxycycline to cover MRSA. 1
• Alternative options include clindamycin if local resistance patterns permit. 1

Surgical Management

Delay surgical debridement for several weeks, not days, as brown recluse bites can progress over days to weeks. 1, 3

• The primary treatment remains rest, ice compresses, and delayed surgical debridement only after the necrotic area has fully demarcated. 1, 3
• Early aggressive surgical intervention is not recommended, as the extent of necrosis may not be apparent initially. 3

Treatments to AVOID

Do NOT use systemic corticosteroids or dapsone—these are associated with slower healing and increased scarring. 4

• A primary care study of 189 patients found that systemic corticosteroids and dapsone were associated with slower healing times. 4
• Dapsone was specifically associated with an increased probability of scarring. 4
• Do not apply suction to the bite site, as this is ineffective and potentially harmful. 2, 1
• Do not apply tourniquets or pressure immobilization bandages, as these may worsen tissue injury. 2, 1

When to Seek Urgent Medical Care

• Seek immediate medical attention if systemic symptoms develop: difficulty breathing, muscle rigidity, dizziness, confusion, or signs of hemolysis or rhabdomyolysis. 1
• Seek medical care if pain extends beyond the bite site or becomes severe, pain is not controlled by over-the-counter medications, or an open wound develops. 2, 1
• Rapidly progressive swelling involving the face, lips, tongue, or throat suggests angioedema requiring emergency intervention. 1

Expected Course and Follow-Up

• Most patients with local symptoms only will recover completely within 24-48 hours, though brown recluse bites can progress over days to weeks. 2, 1
• Follow-up within 24 hours either by phone or office visit is advised to monitor for progression. 1
• Monitor for signs of secondary infection requiring prompt medical attention. 2, 1
• Only 21% of brown recluse spider bites result in permanent scarring when managed appropriately. 4