Black Widow Spider

The Black Widow spider is the most venomous spider in the United States. There have been no reported deaths in the United States in the last twenty years. When bitten the presentation is similar to an " acute abdomen. " In medicine this is when someone presents with severe abdominal pain often mimicking an appendix attack. We target symptoms and treatment.

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The black widow spider is of the family Theridiiae. The males are much smaller. They are noted for their diet of other spiders but have been known to kill small lizards as well as insects. The female can and will devour the male, however, this is rare and not commonplace. Females have a jet black body with a sort of sheen to it and a striking red hourglass on its abdomen. The males are smaller and their hourglass is faint and can be non-existent.

They can be found under logs, rocks, and in dark corners of a garage and old buildings. It is not uncommon for them to be located in an outhouse or privy and have been noted to biting a male on his genitalia when sitting. The Black Widow is found in every state except Alaska.


Latrodectism is the syndrome when one is bit by a Black Widow. A syndrome is a group of symptoms that present in a constant specific way. Instead of local inflammation at the bite site as in a Recluse bite, the widow often has sustained muscle spasm. It is a neurotoxin that can cause hypertension, muscle spasm, and can mimic an acute abdomen. An acute abdomen is sudden pain in the belly that can be severe very much like an appendicitis.

It should be noted as per Dr. Paul Auerbach, Author of Wilderness Medicine , there was a nine year period in the United States where 23,400 Black Widow bites were recorded. Of these 23,400 cases, 33.5% had moderate symptoms, 1.5% had major symptoms and ZERO deaths were reported.

Symptoms of the Black Widow Bite

  1. Abdominal or back pain
  2. Diaphoresis ( sweating )
  3. Headache
  4. Abdominal spasm
  5. Priapism ( sustained erection )
  6. Rash may appear 2-10 days later
  7. Hypertension

Treatment of Black Widow Bites

As recently as 15 years ago, Calcium Gluconate was used. It has since been discontinued and does not improve outcome.


  1. Clean the area
  2. Application of ice
  3. Severe pain and muscle spasm treated with IV narcotics and benzodiazepines.
  4. Hypertension with antihypertensives
  5. In severe cases, an antivenin is available although not widely distributed. Some concerns seen in the literature with allergic reactions to the anti-venom.