Intralesional or systemic steroids are controversial. Antivenin is available. Only females envenomate humans. They are jet black with a globe shaped abdomen on which there is the notorious red hourglass on the ventral surface. The body measures up to 1.5cm with a 4cm leg span.
Black widows bite humans that contact their web.
The venom is a neurotoxin, causes release of acetylcholine at neuromuscular junction and blockage of reuptake. There is little local damage or necrosis. The bite usually is perceived as a sharp pinprick. Two red puncta are frequently seen at the site with mild erythema. Severe myalgias and muscle cramping develop.