Wednesday, February 24, 2010
Black Widow Spider Bites
8:22 PM | 
Diposkan oleh
Hermanto
We can found Widow spiders (genus Latrodectus) throughout the world. At least one of five species inhabits all areas of the United States except Alaska. The most popular widow spider is the black widow (Latrodectus mactans).
Female spiders (Black widow) has a leg span of 1 to 4 cm and a shiny black body with a distinctive red ventral marking (often hourglass shaped). Variations in color occur among other species, some of them appearing brown or red and some without the ventral marking. The nonaggressive female widow spider bites in defense. Males are too small to bite through human skin.
Widow spiders produce neurotoxic venom with minimal local effects with major component is α-latrotoxin that acts at presynaptic terminals by enhancing release of neurotransmitters.
When they bite us, may be felt painless or felt as a “pinprick.” Local findings are minimal.
Neuromuscular symptoms may occur as early as 30 minutes after the bite such as :
· Severe pain and spasms of large muscle groups
· Abdominal cramps and rigidity
· Dyspnea as the result from chest wall muscle tightness
· Hypertension, diaphoresis, and tachycardia as the result of autonomic stimulation.
· Other symptoms : nausea, vomiting, headache, paresthesias, fatigue, and salivation.
· Symptoms usually peak at several hours and resolve in 1 to 2 days.
· Death is an unusual result of widow spider bites.
For mild bites, we can treat with local wound care such as cleansing, intermittent application of ice, and tetanus prophylaxis as needed. In some cases, we can use narcotics and benzodiazepines to relieve muscular pain.
In the United States, antivenom derived from horse serum is available (Black Widow Spider Antivenin, Merck & Co., West Point, PA). We must be careful use this antivenom because this antivenom can cause anaphylactoid reactions or serum sickness. So, before use antivenom, better we do skin testing for possible allergy. In some studies have demonstrated that antivenom can decrease hospital stay.
