What is the treatment for a spider bite?

Spider Bite Treatment

For most spider bites, treatment consists of thorough wound irrigation with water, ice application with a barrier, over-the-counter pain medications, antibiotic ointment, and a clean dressing—antibiotics are NOT routinely needed unless clear signs of secondary bacterial infection develop. 1, 2

Immediate First Aid

• Irrigate the wound thoroughly with copious amounts of warm or room temperature water until all foreign matter is removed 1, 2
• Apply ice to the bite site with a clean barrier between ice and skin for local pain relief 1, 2
• Remove rings and constricting objects immediately from the affected extremity, as swelling may occur 1, 2
• Apply antibiotic ointment and cover with a clean occlusive dressing to improve healing and reduce infection risk 1, 2
• Elevate the affected area to accelerate healing and reduce swelling 2

Pain Management

• Over-the-counter acetaminophen or NSAIDs are recommended for pain control 1, 2
• Topical lidocaine 5% can be applied if the skin is intact for additional pain relief 2
• Oral antihistamines can reduce itching and swelling 2

Critical Pitfall: When Antibiotics Are Actually Needed

Swelling in the first 24-48 hours is caused by inflammatory mediator release, NOT infection—do not prescribe antibiotics prophylactically. 1, 2

Signs requiring antibiotics include:

• Progressive erythema extending beyond the initial bite site 2
• Purulent discharge from the wound 2
• Systemic signs of infection such as fever or elevated white blood cell count 2

Antibiotic selection when infection is confirmed:

• First-line oral therapy: Trimethoprim-sulfamethoxazole or doxycycline to cover MRSA 2
• Alternative option: Clindamycin if local resistance patterns permit 2

When to Seek Immediate Medical Care

• Systemic symptoms including difficulty breathing, muscle rigidity, dizziness, or confusion 1, 2
• Rapidly progressive swelling involving the face, lips, tongue, or throat suggesting angioedema 2
• Severe pain extending beyond the bite site or uncontrolled by over-the-counter medications 1, 2
• Open wound development or signs of infection 1

Special Considerations for Brown Recluse Spider Bites

Brown recluse bites can cause painful ulcerated wounds that progress over days to weeks, sometimes with hemolysis and rhabdomyolysis 2

• Primary treatment: Rest, ice compresses, and delayed surgical debridement (several weeks after the bite) 2, 3
• Avoid early surgical intervention—debridement should be delayed for several weeks to allow demarcation of necrotic tissue 3
• Dapsone has been historically used but is controversial 3, 4

What NOT to Do

• Do not apply suction to the bite site—this is ineffective and potentially harmful 1, 2
• Do not apply tourniquets or pressure immobilization bandages—these may worsen tissue injury 1, 2
• Do not assume antibiotics are needed for swelling around the bite site in the first 24-48 hours 1, 2
• Do not close infected wounds 2

Expected Recovery Timeline

• Most patients with local symptoms only will recover completely within 24-48 hours 1, 2
• Continue pain management with over-the-counter medications as needed for several days 1, 2
• Follow-up within 24 hours either by phone or office visit is advised 2
• Monitor for signs of secondary infection requiring prompt medical attention 1