black widow spider bite [AS, blac + widewe; ME, spithre + AS, bitan] , the bite of the spider species Latrodectus mactans, a poisonous arachnid found in many parts of the world. Black widow venom contains some enzymatic proteins, including a peptide that affects neuromuscular transmission. The bite is perceived as a sharp pinprick pain, followed by a dull pain in the area of the bite; restlessness; anxiety; sweating; weakness; and drooping eyelids. Muscular rigidity starts at the location of the bite and moves in peripherally to the chest. Small children, elderly adults, or persons with heart disorders are most severely affected and may require hospitalization and the administration of an antivenin. Immediate treatment includes keeping the victim quiet and immobilizing the bite area at the level of the heart.
