Brown recluse spider bites.

BACKGROUND Brown recluse spider bites are a serious medical problem in the southeastern United States. Although most bites are asymptomatic, envenomation can result in a constellation of systemic symptoms referred to as loxoscelism. Patients can also develop necrotic skin ulcers (necrotic arachnidism). These ulcers are often difficult to heal and can require skin grafting or amputation of the bitten appendage. METHODS A search of the literature was performed using the search words "spider envenomation," "brown recluse spider bites," and "arachnid envenomation." RESULTS AND CONCLUSIONS Most brown recluse spider bites are asymptomatic. All bites should be thoroughly cleansed and tetanus status updated as needed. Patients who develop systemic symptoms require hospitalization. Surgical excision of skin lesions is indicated only for lesions that have stabilized and are no longer enlarging. Steroids are indicated in bites that are associated with severe skin lesions, loxoscelism, and in small children. Dapsone should be used only in adult patients who experience necrotic arachnidism and who have been screened for glucose-6-phosphate dehydrogenase deficiency. Topical nitroglycerin can be of value in decreasing the enlargement of necrotic skin ulcers.