History
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. [7, 8] Within about 1 hour, systemic symptoms begin and may last for a few days.
Muscle cramping may occur locally or extend into large muscle groups, such as the abdomen, back, chest, and thighs. Case reports suggest involvement of smooth muscles in the bronchi and endometrium.
Other symptoms may include nausea and vomiting, headache, and anxiety. Some patients describe pavor mortis, a feeling of impending doom.
Physical Examination
Abnormal vital signs may include hypertension, tachypnea, tachycardia, and, occasionally, hyperthermia.
Diaphoresis, locally and/or remote from the site of envenomation, may occur.
Tiny fang marks may be visible at the bite site
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.
Severe muscle cramping, the hypertoxic myopathic syndrome, is common, generally localized to the same half of the body as the envenomation. Abdominal rigidity following lower extremity bites 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. [9]
Complications
Complications may include the following:
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Complications may include the following:
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Respiratory difficulty, reactive airway exacerbation
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Spontaneous abortion or preterm labor
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Hypertensive emergency with or without associated seizures (isolated normotensive seizures have not been described), acute myocardial infarction
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Rhabdomyolysis
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Ileus [10]
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Compartment syndrome (rare) [13]
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Electrocardiographic abnormalities [14]
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Toxic myocarditis (rare) [15]
Also see Treatment/Complications.
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Black widow spider (Latrodectus mactans) and offspring. Photo by Sean Bush, MD.
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Female black widow spider guarding an egg case; species Latrodectus mactans. By Chuck Evans (mcevan). [CC BY 2.5 (https://creativecommons.org/licenses/by/2.5)], courtesy of Wikimedia Commons (https://commons.wikimedia.org/wiki/File:Black_Widow_Spider_07-04-20.jpg).
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Female black widow spider, Latrodectus mactans, in the process of spinning her web on a tree branch. Note the characteristic red hourglass located on her inferior abdominal surface. This marking can vary in coloration from yellowish to shades of orange and red and, at times, white. The female’s body is an overall shiny jet-black in color. This spider was found on a farm in the US state of Georgia. By James Gathany (http://phil.cdc.gov/phil/) [Public domain], courtesy of Wikimedia Commons (https://commons.wikimedia.org/wiki/File:Black_widow_spider_9854_lores.jpg).
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A redback spider (Latrodectus hasseltii) female, found in suburban Sydney, New South Wales, Australia. By Toby Hudson [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], courtesy of Wikimedia Commons (https://commons.wikimedia.org/wiki/File:Latrodectus_hasseltii_close.jpg).
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Young female Latrodectus tredecimguttatus; photo taken in Croatia by K. Korlevic. No machine-readable author provided. Kork~commonswiki assumed (based on copyright claims). [Public domain], via Wikimedia Commons (https://commons.wikimedia.org/wiki/File:Latrodectus_tredecimguttatus_female.jpg).
