What is the treatment for a spider bite (arachnidism)?

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From the Guidelines

For most spider bites, cleaning the area with soap and water, applying an ice pack to reduce pain and swelling, and taking over-the-counter pain relievers like acetaminophen or ibuprofen as needed is the recommended treatment. Elevating the affected limb if possible can also help reduce swelling. It is essential to note that for common spider bites, this home treatment is usually sufficient [ 1 ]. However, if you suspect a bite from a dangerous spider like a black widow or brown recluse, seeking immediate medical attention is crucial. Signs requiring emergency care include severe pain, spreading redness beyond 2 inches, difficulty breathing, muscle cramps, sweating, nausea, or a growing ulcer at the bite site [ 1 ].

Key Considerations for Treatment

  • Cleaning the bite area with soap and water to prevent infection
  • Applying an ice pack to reduce pain and swelling
  • Using over-the-counter pain relievers like acetaminophen or ibuprofen as needed
  • Elevating the affected limb if possible to reduce swelling
  • Seeking medical care if symptoms worsen or if there are signs of a severe reaction

According to the 2024 American Heart Association and American Red Cross guidelines for first aid [ 1 ], emergency services should be called if a person bitten by a spider or stung by a scorpion develops symptoms throughout the body such as difficulty breathing, muscle rigidity, dizziness, or confusion. Additionally, a person bitten by a spider or stung by a scorpion should seek medical care if pain extends beyond the site of the bite/sting, 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 [ 1 ].

Special Considerations

  • Children, elderly people, and those with compromised immune systems should be monitored more closely after any spider bite as they may have more severe reactions
  • Dangerous spider bites require medical intervention because their venom can cause tissue damage or systemic reactions
  • Most spider bites heal within a week with basic care, but it's essential to be aware of the signs of a severe reaction and seek medical help if necessary [ 1 ].

From the Research

Diagnosis and Management of Spider Bites

  • Spider bites can be difficult to diagnose as the spider is often not seen at the time of the suspected bite, and should be labeled as arthropod bites, vector unknown 2
  • At least 60 species of spiders have been implicated in human bites, with most causing minimal medical importance and requiring little treatment 2

Treatment Options

  • For black widow spider bites, treatment is usually symptomatic with a combination of opioid analgesics and muscle relaxants 3
  • In severe cases, an equine IgG antiserum is available for black widow spider bites 3
  • For brown recluse and Hobo spider bites, intensive medical management may be required due to severe cutaneous and systemic reactions 2

Clinical Manifestations

  • Black widow spider bites can cause severe neurologic problems, as well as muscle pain, diaphoresis, tachycardia, flushing, and hypertension 3
  • Brown recluse spider bites can cause dermonecrosis, secondary infection, and allergic reactions 2

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Spider bites.

The Journal of the American Board of Family Practice, 1995

Research

The black widow spider bite: differential diagnosis, clinical manifestations, and treatment options.

The Journal of the Louisiana State Medical Society : official organ of the Louisiana State Medical Society, 2015

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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