What is the treatment for a brown recluse spider bite?

Treatment for Brown Recluse Spider Bites

Emergency services should be called if a person bitten by a brown recluse spider develops systemic symptoms such as difficulty breathing, muscle rigidity, dizziness, or confusion. 1

Initial Assessment and Management

When to Seek Medical Care

• Seek immediate medical attention if:
  • Systemic symptoms develop (difficulty breathing, muscle rigidity, dizziness, confusion)
  • Pain extends beyond the bite site
  • Pain becomes severe and uncontrolled by over-the-counter medications
  • An open wound develops 1

First Aid Measures

• Thoroughly clean the bite site with soap and water
• Update tetanus status as needed 2
• Apply ice to reduce local pain and swelling 1
• Elevate the affected area if possible

Treatment Algorithm

For Local Reactions (Most Common)

1. Symptomatic Treatment:

   • Apply cold compresses to reduce pain and swelling 1
   • Use over-the-counter pain medications:
     • Acetaminophen or NSAIDs for pain control 1
     • Oral antihistamines to reduce itching 1

2. Wound Care:

   • Keep the wound clean
   • Monitor for signs of secondary infection
   • Avoid antibiotics unless there is evidence of secondary infection 1

For Developing Necrotic Lesions

1. Medical Management:

   • Dapsone may be used in adults with necrotic arachnidism (only after screening for glucose-6-phosphate dehydrogenase deficiency) 2
   • Systemic corticosteroids are indicated for:
     • Severe skin lesions
     • Systemic symptoms (loxoscelism)
     • Small children 2

2. Advanced Wound Care:

   • Surgical excision is indicated ONLY for lesions that have stabilized and are no longer enlarging 2
   • Topical nitroglycerin may decrease enlargement of necrotic skin ulcers 2
   • For non-healing wounds (2-3 months after bite), hyperbaric oxygen therapy may be beneficial 3

For Systemic Symptoms (Loxoscelism)

1. Immediate Hospitalization Required 2
2. Treatment may include:
   • Intravenous fluids
   • Systemic corticosteroids to treat massive hemolysis 4
   • Close monitoring for hemolysis and rhabdomyolysis 1

Important Considerations and Pitfalls

Common Misdiagnoses and Pitfalls

• Many conditions are misdiagnosed as brown recluse bites
• Antibiotics are often unnecessarily prescribed; they are NOT indicated unless there is evidence of secondary infection 1
• Premature surgical intervention can worsen outcomes; delay surgery until lesions have stabilized 2

Special Populations

• Children may develop more severe reactions and should be monitored closely 2
• Patients with pre-existing conditions may be at higher risk for complications

Monitoring

• Monitor bite sites for:
  • Increasing pain or swelling
  • Development of necrotic tissue
  • Signs of systemic involvement (fever, rash, joint pain)
  • Progression of any skin lesion beyond 24-48 hours

Brown recluse spider bites can range from mild local reactions to severe necrotic wounds or systemic illness. While most bites heal without intervention, proper wound care and monitoring for systemic symptoms are essential to prevent complications.