Black Widow Spider Bite

ExitCare ImageThe adult female black widow spider has a black body about ½ inch (1.2 cm) long with an orange-red hourglass shape on her belly. Black widow spider bites can be serious and life-threatening.


Symptoms usually develop in 15 minutes to 2 hours after the bite. Symptoms usually peak in 3 hours to 1 day and may include:

  • Muscle cramps. These may occur anywhere in the body, including the abdomen.

  • Nausea and vomiting.

  • Dizziness.

  • Heavy sweating.

  • Shaking.

  • Restlessness.

  • Fever.

  • Trouble breathing.

  • Chest pain.

  • Swelling or a rash around the bite.


Serious reactions may require hospitalization. Your caregiver may give you an antivenom injection to help reduce pain. This is only done for very severe reactions that are not effectively treated with other medicines. There is a chance of having an allergic reaction to the antivenom since it is derived from horse serum.


  • Do not scratch the bite area. Keep the area clean and covered with an adhesive bandage or sterile gauze bandage.

  • Wash the area 3 times per day in warm, soapy water or as directed by your caregiver.

  • Put ice or cool compresses on the bite area.

  • Put ice in a plastic bag.

  • Place a towel between your skin and the bag.

  • Leave the ice on for 20 minutes, 4 times a day for the first 2 days or as directed.

  • Keep the bite area elevated above the level of your heart. This helps reduce redness and swelling.

  • Only take over-the-counter or prescription medicines for pain, discomfort, or fever as directed by your caregiver.

  • Watch the bite area closely for worsening pain, swelling, redness, or pus.

You may need a tetanus shot if:

  • You cannot remember when you had your last tetanus shot.

  • You have never had a tetanus shot.

  • The injury broke your skin.

If you get a tetanus shot, your arm may swell, get red, and feel warm to the touch. This is common and not a problem. If you need a tetanus shot and you choose not to have one, there is a rare chance of getting tetanus. Sickness from tetanus can be serious.


  • You have muscle cramps or abdominal pain or cramps.

  • You develop rapid breathing or a rapid heartbeat.

  • You become extremely restless or confused.

  • You have chest pain.

  • You feel faint, lightheaded, or you feel generally ill (malaise).

  • You develop pain, soreness, redness, swelling, or drainage from the bite.

  • You have a fever.


  • Understand these instructions.

  • Will watch your condition.

  • Will get help right away if you are not doing well or get worse.