Funnel-web spider bite

Definition

This article describes the effects of a bite from the funnel-web spider. Male funnel-web spider bites are more toxic than bites by females. The class of insects to which the funnel-web spider belongs, contains the largest number of venomous species known.

This article is for information only. DO NOT use it to treat or manage a bite from this type of spider. If you or someone you are with has an exposure, call the local emergency number (such as 911), or the local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States.

Poisonous Ingredient

The venom in the funnel-web spider contains the toxin called delta hetatoxin.

Where Found

Specific types of funnel-web spiders are found in southeast Australia, around Sydney. Others are found in Europe, New Zealand, and Chile. They are not native to the United States, although some people may keep them as exotic pets. The webs that are built by this group of spiders consist of funnel-shaped tubes that extend into a protected space such as a hole in a tree or a burrow in the ground.

Symptoms

Funnel-web spider bites are very painful and dangerous. They have been known to cause these symptoms in different parts of the body:

EYES, EARS, NOSE, AND THROAT

  • Drooling
  • Drooping eyelids
  • Double vision
  • Swallowing difficulty
  • Tingling or numbness in the mouth or lips within 10 to 15 minutes

HEART AND BLOOD

  • Collapse (shock)
  • Rapid heart rate

LUNGS

  • Difficulty breathing

MUSCLES AND JOINTS

  • Joint pain
  • Severe muscle spasms, usually in the legs and belly area

NERVOUS SYSTEM

  • Agitation
  • Confusion
  • Coma (lack of responsiveness)
  • Headache
  • Numbness of mouth and lips
  • Tremors (shaking)
  • Shivering (chills)

SKIN

  • Heavy sweating
  • Redness around the site of the bite

STOMACH AND INTESTINES

  • Diarrhea
  • Nausea and vomiting

Home Care

Funnel-web spider bites are very toxic. Seek medical help right away. Call 911 or the Poison Control Center for guidance.

Immediate treatment of a bite consists of the following 4 steps, which are modeled after the Australian snake bite treatment.

  1. Clean the area with soap and water and wrap the length of the bitten extremity with an elastic bandage.
  2. Attach a splint to the bitten extremity to immobilize the area.
  3. Keep the victim from moving.
  4. Keep the bandage in place as the victim is transported to the nearest hospital or emergency treatment center.

Before Calling Emergency

Have this information ready:

  • Person's age, weight, and condition
  • Time the bite occurred
  • Area on the body where the bite occurred
  • Type of spider, if possible

Poison Control

Your local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. This national hotline will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

What to Expect at the Emergency Room

The health care provider will measure and monitor the person's vital signs, including temperature, pulse, breathing rate, and blood pressure. The wound will be treated as appropriate.

The person may receive:

  • Antivenin, a medicine to reverse the effects of the venom, if available
  • Blood and urine tests
  • Breathing support, including oxygen, tube through the mouth into the throat, and breathing machine (ventilator)
  • Chest x-ray
  • ECG (electrocardiogram, or heart tracing)
  • Intravenous fluids (IV, or through a vein)
  • Medicines to treat symptoms

Outlook (Prognosis)

Funnel-web spider bites can be life threatening, especially in children. They must be treated quickly with antivenin by an experienced provider. Even with appropriate and quick treatment, symptoms may last for several days to weeks. The original bite may be small and may progress to a blood blister and look like a bull's eye. (This is similar to the appearance of a brown recluse spider bite.)

The area affected by the bite may become deeper. Additional symptoms such as fever, chills, and other signs of additional organ system involvement may develop. Deep scarring may occur and surgery may be needed to improve appearance of the scar.

References

Boyer LV, Binford GJ, Degan JA. Spider bites. In: Auerbach PS, Cushing TA, Harris NS, eds. Auerbach's Wilderness Medicine. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 43.

Curtis AM. Erickson TB. Venomous animal injuries. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 53.

Isbister G. Spider bite. In: Cameron P, Little M, Mitra B, Deasy C, eds. Textbook of Adult Emergency Medicine. 5th ed. Philadelphia, PA: Elsevier; 2020:chap 26.3.

White J. Envenomation. In: Penman ID, Ralston SH, Strachan MWJ, Hobson RP, eds. Davidson's Principles and Practice of Medicine. 24th ed. Philadelphia, PA: Elsevier; 2023:chap 11.

Review Date: 7/1/2023
Reviewed By: Jesse Borke, MD, CPE, FAAEM, FACEP, Attending Physician at Kaiser Permanente, Orange County, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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