brown recluse spider
The trivial name for a poisonous spider, Loxosceles reclusa, which lives in warmer parts of the US, and is identified by the presence of a characteristic violin-like marking on its dorsal surface. Its cousin, L laeta, is native to South America and more toxic than L reclusa.
• Local symptoms Cyanosis, necrosis, pustule or bullae, rimmed by ischaemia and erythaema expanding to 20 cm over weeks to months, accompanied by lymphadenitis
• Systemic symptoms Fever, chills, headache, nausea, vomiting, dizziness, purpura, myalgia, arthralgia, DIC, and potentially fatal intravascular haemolysis with haemoglobulinuria and acute renal failure
Mechanism of injury Loxoscles venom contains several necrolysing enzymes
Management Surgical excision of bite site ASAP, which limits the spread of toxins, split thickness skin grafting, corticosteroids, antihistamines; with advanced lesions, tetanus immunisation is required, bacterial culture, and broad-spectrum antibiotics