What is the treatment for arachnid (arthropopper) envenomation, specifically spider bite?

From the Guidelines

To treat a spider bite, first clean the area with mild soap and water, then apply a cold compress for 10 minutes to reduce pain and swelling, and take over-the-counter pain relievers like acetaminophen or ibuprofen according to package directions. This approach is based on the most recent guidelines from the American Heart Association and American Red Cross for first aid, as outlined in the 2024 guidelines published in Circulation 1.

Key Considerations for Treatment

• Clean the bite area with mild soap and water to prevent infection
• Apply a cold compress to reduce pain and swelling
• Use over-the-counter pain relievers such as acetaminophen or ibuprofen for pain management
• Elevate the affected area if possible to reduce swelling
• Apply an antibiotic ointment to prevent infection and cover with a bandage

When to Seek Medical Attention

It is crucial to seek immediate medical attention if severe symptoms develop, such as:

• Intense pain
• Spreading redness
• Difficulty breathing
• Severe swelling
• Muscle cramps
• Suspected bite from a black widow or brown recluse spider, as these can cause serious reactions requiring medical intervention, possibly including antivenom treatment 1.

Additional Guidance

For children, it is essential to adjust medication dosages according to age and weight as indicated on product packaging. The use of topical lidocaine, ice, and nonsteroidal anti-inflammatory agents can also be beneficial for local pain relief, as supported by studies on scorpion stings 1. However, the primary approach should focus on basic first aid measures and monitoring for severe symptoms that may necessitate advanced medical care.

From the Research

Treatment for Arachnid Envenomation

The treatment for arachnid envenomation, specifically spider bites, varies depending on the species of spider and the severity of the bite.

• For brown recluse spider bites, treatment includes:
  • Rest, ice compresses, antibiotics, dapsone, and surgery delayed for several weeks for dermonecrosis 2
  • Systemic corticosteroids may be helpful in treating systemic loxoscelism 2
  • Steroids are indicated in bites that are associated with severe skin lesions, loxoscelism, and in small children 3
  • Dapsone should be used only in adult patients who experience necrotic arachnidism and who have been screened for glucose-6-phosphate dehydrogenase deficiency 3
  • Topical nitroglycerin can be of value in decreasing the enlargement of necrotic skin ulcers 3
• For black widow spider bites, treatment includes:
  • Pain control, muscle relaxants, and calcium gluconate 2
  • Antivenom (Antivenin Latrodectus mactans) is available and effective, but is often withheld because of a fear of acute hypersensitivity reactions 4
  • Antivenom can be used safely and effectively in symptomatic black widow spider envenomation 4

General Treatment

• All bites should be thoroughly cleansed and tetanus status updated as needed 3
• Patients who develop systemic symptoms require hospitalization 3
• Surgical excision of skin lesions is indicated only for lesions that have stabilized and are no longer enlarging 3
• Anti-venom administration is the most useful treatment for spider bite 5