Treatment for Spider Bites
For most spider bites, treatment consists of thorough wound irrigation with water, ice application with a barrier, antibiotic ointment with occlusive dressing, and over-the-counter pain medications—antibiotics are NOT routinely needed unless clear signs of infection develop. 1
Initial Wound Care
- Irrigate the bite wound thoroughly with a large volume of warm or room temperature potable water until all foreign matter is removed. 1
- Apply antibiotic ointment and cover with a clean occlusive dressing to improve healing and reduce infection risk. 1
- Remove rings and any constricting objects from the affected extremity immediately, as swelling may occur. 1, 2
- Elevate the affected area to accelerate healing and reduce swelling. 2
Pain and Swelling Management
- Apply ice to the bite site for local pain relief, always using a clean barrier between ice and skin. 1
- Use over-the-counter acetaminophen or NSAIDs for pain control. 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
- For severe large local reactions with extensive swelling, a short course of oral corticosteroids may be considered. 2
Critical Pitfall: When Antibiotics Are Actually Needed
Large swelling in the first 24-48 hours is caused by allergic inflammation, NOT infection—do not prescribe antibiotics routinely. 2 This is one of the most common errors in spider bite management.
- Universal prophylaxis with antibiotics is not recommended for bite wounds. 2
- Only consider antibiotics if clear signs of secondary bacterial infection develop: 2
- Progressive erythema extending beyond the initial bite site
- Purulent discharge
- Systemic signs such as fever or elevated white blood cell count
When to Seek Immediate Medical Care
Patients require urgent evaluation if: 1, 2
- 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)
- Systemic symptoms develop (difficulty breathing, dizziness, confusion, muscle rigidity)
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, as these may worsen tissue injury. 1, 2
- Do not assume antibiotics are needed for swelling around the bite site, as swelling is typically caused by mediator release, not infection. 1
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 during the recovery period. 1
Special Considerations for Venomous Spider Bites
For brown recluse spider bites that develop dermonecrosis within 72-96 hours, treatment includes rest, ice compresses, antibiotics, dapsone, and surgery delayed for several weeks. 3, 4 For black widow bites causing muscle cramping and neuromuscular symptoms, pain control, muscle relaxants, and calcium gluconate are generally adequate, with antivenin reserved for severe reactions. 3, 4