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 with occlusive dressing, and elevation of the affected area—antibiotics are NOT routinely indicated unless clear signs of 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 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
• Elevate the affected area to reduce swelling and accelerate healing 2
• Apply antibiotic ointment and cover with a clean occlusive dressing to improve healing and reduce infection risk 1, 2

Pain Management

• Over-the-counter acetaminophen or NSAIDs are recommended 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

Critical Pitfall: When Antibiotics Are NOT Needed

Swelling in the first 24-48 hours is caused by allergic inflammation and mediator release, NOT infection—do not assume antibiotics are needed. 1, 2 Universal prophylactic antibiotics are not recommended for bite wounds 2

When to Seek Emergency Medical Care

Seek immediate medical attention if any of the following develop:

• Systemic symptoms: difficulty breathing, bronchospasm, dizziness, confusion, muscle rigidity, syncope, or hypotension 2
• Rapidly progressive swelling involving face, lips, tongue, or throat 2
• Severe pain extending beyond the bite site or uncontrolled by over-the-counter medications 1, 2
• Open wound development 1

When Antibiotics ARE Indicated

Antibiotics should only be considered if clear signs of secondary bacterial infection develop 2:

• 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

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 close infected wounds 2
• Do not place objects in the mouth of someone having a seizure 1

Special Considerations for Venomous Spiders

Brown Recluse (Loxosceles) Bites

• Dermonecrosis typically develops within 72-96 hours 3
• Treatment includes rest, ice compresses, and dapsone for severe cases 3
• Delay surgical debridement for several weeks to allow full demarcation of necrotic tissue 3
• Systemic corticosteroids may be helpful for rare systemic loxoscelism with massive hemolysis 3
• Hyperbaric oxygen therapy may be considered for chronic nonhealing wounds that fail standard therapy 4

Black Widow (Latrodectus) Bites

• Produces minimal skin changes but causes muscle cramping, pain, and neuromuscular symptoms 3, 5
• Treatment includes pain control, muscle relaxants (methocarbamol, diazepam), and calcium gluconate 3, 5, 6
• Specific antivenom is available for severe cases 3, 5

Expected Recovery Timeline

• Most patients with local symptoms only 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 by phone or office visit is advised 2
• Monitor for signs of secondary infection requiring prompt medical attention 1