Widow Spider Envenomation Clinical Presentation

Updated: Sep 19, 2018
  • Author: Sean P Bush, MD, FACEP; Chief Editor: Joe Alcock, MD, MS  more...
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Initial pain at the bite site is generally trivial and may go unnoticed. It commonly is described as a pinch or pinprick; however, infants may present with unexplained crying. [5, 6]  Within about 1 hour, systemic symptoms begin and may last for a few days.

Muscle cramping may occur locally, around the area bitten. It may extend into large muscle groups, such as the abdomen, back, chest, and thighs. Case reports suggest involvement of smooth muscles, such as bronchial or endometrial.

Other symptoms may include nausea and vomiting, headache, and anxiety.


Physical Examination

Abnormal vital signs may include hypertension and tachycardia.

Diaphoresis, locally, around the area bitten, or remote from the site of envenomation, may occur.

Tiny fang marks may be visible.

Local effects are usually limited to a small circle of redness and/or induration around the immediate bite site. A central reddened fang puncture site surrounded by an area of blanching and an outer halo of redness is described as a having a target appearance.

Abdominal rigidity may mimic an acute abdomen.

Neurologic effects, including mild weakness, fasciculations, and ptosis, have been described.

Latrodectus facies, characterized by spasm of facial muscles, edematous eyelids, and lacrimation may occur. This can be mistaken for an allergic reaction.

Bronchorrhea and pulmonary edema have been described in Europe and South Africa.



Complications may include the following:

  • Respiratory difficulty, reactive airway exacerbation
  • Spontaneous abortion or preterm labor
  • Hypertensive emergency with or without associated seizures (isolated normotensive seizures have not been described), acute myocardial infarction
  • Rhabdomyolysis
  • Priapism (rare)
  • Compartment syndrome (rare) [7]
  • Toxic myocarditis (rare)

Also see Treatment/Complications.