The black widow spider is a small, poisonous, eight-legged arachnid found in the Western hemisphere. The primary distinguishing feature of the black widow spider is a tiny, reddish, hourglass-shaped mark on its stomach. The black widow spider may bite if it is inadvertently touched, trapped or frightened by a human. Though a bite from this spider is rarely fatal, the effects of a black widow spider bite may require emergency medical attention.
Skin Rash or Swelling
When a black widow spider bites the skin, a person can experience a sharp, rapid sensation of pain, similar to that of a pinprick. Within 30 to 40 minutes, the skin surrounding the bite mark can appear unusually red, irritated, inflamed or swollen, warns KidsHealth, a children's health information website established by the Nemours Foundation. The skin rash may appear as a red ring or circle and can be tender to the touch.
Muscle Pain, Cramping or Stiffness
A black widow spider can inject a toxic substance through its fangs when it bites. This toxin can affect a person's normal nerve and muscle function. As a result, people bitten by a black widow spider can experience severe muscle pain, cramping or stiffness, report medical experts with the University of Maryland Medical Center. These effects of a black widow spider bite can contribute to weakness, paralysis or involuntary movement of the muscles--particularly the muscles within the legs. Elderly adults and young children are at the highest risk of developing severe symptoms following a black widow spider bite, warn health professionals with the California Poison Control System. People who develop any of these effects of a black widow spider bite should be evaluated by a medical professional immediately.
Flu-like Symptoms
After sustaining a bite from a black widow spider, people can develop flu-like symptoms that can include fever, headache, sweating, chills and dizziness, explains health professionals with UMMC and MayoClinic.com. These effects of a black widow spider bite can arise within a few hours following injury. People who develop these symptoms after receiving a spider bite should consult a physician as soon as possible.
Stomach Upset
Stomach upset symptoms, including nausea and vomiting, can arise in certain people as an effect of a black widow spider bite, warns MayoClinic.com. Nausea and vomiting can be uncomfortable and typically contribute to a temporary loss of appetite. People who become nauseous or begin to vomit after being bitten by a black widow spider should see a doctor as soon as possible.
