What is the treatment for a Loxosceles reclusa (brown recluse spider) bite?

From the Guidelines

The primary treatment for a brown recluse spider bite is supportive care and close monitoring, with immediate medical attention recommended if a bite is suspected. According to the 2024 American Heart Association and American Red Cross guidelines for first aid 1, bites from brown recluse spiders can cause painful ulcerated wounds that progress over days to weeks, sometimes associated with hemolysis and rhabdomyolysis. Key steps in treatment include:

• Cleaning the bite area with soap and water
• Applying a cold compress to reduce pain and swelling
• Taking over-the-counter pain relievers like acetaminophen or ibuprofen as needed, as recommended by the guidelines 1
• Elevating the affected area if possible
• Watching for signs of infection or systemic symptoms A doctor may prescribe antibiotics if infection develops. In severe cases, they might use dapsone to limit tissue damage, though this is controversial. Rarely, surgical debridement may be necessary for extensive necrosis. It is essential to avoid home remedies or applying heat, which can worsen tissue damage, and to seek medical care if pain extends beyond the site of the bite, becomes severe, and is not controlled by over-the-counter pain medications; if an open wound develops; or if the person experiences symptoms throughout the body, as recommended by the guidelines 1.

From the Research

Treatment Options for Brown Recluse Spider Bites

• The treatment for brown recluse spider bites remains controversial, with multiple options available but little evidence of their effectiveness 2
• Common treatment approaches include:
  • Topical nitroglycerine patches
  • Vitamin C tablets
  • Corticosteroids
  • Dapsone
  • Hyperbaric oxygen therapy (HBOT) for nonhealing wounds 3
  • Curettage of the subcutaneous tissue in the necrotic area of the lesion 4
• Treatment must be individually tailored, with proper treatment, reassurance, and rapid follow-up helpful in reducing cutaneous and psychologic discomfort associated with brown recluse spider bites 5

Specific Treatment Considerations

• Systemic corticosteroids and dapsone may be associated with slower healing and increased probability of scarring 2
• HBOT may be a valuable therapeutic tool for nonhealing wounds, even months after the bite 3
• In severe cases, antibiotics, steroids, blood transfusions, and plasma exchange may be necessary to manage systemic symptoms such as hemolytic anemia and disseminated intravascular coagulation 6

General Principles of Treatment

• The objectives of treatment are to prevent skin necrosis and the need for reconstructive surgery 4
• Early medical attention and treatment can help reduce the severity of symptoms and improve outcomes 2
• Treatment should be based on symptoms, with management tailored to the individual patient's needs 6