SHORT COMMUNICATION SOUTH AMERICAN RATTLESNAKE BITE (CROTALUS DURISSUS SP) WITHOUT ENVENOMING: INSIGHTS ON DIAGNOSIS AND TREATMENT NILTON ALVES DE REZENDE, 1,4 * FELIPE MAIA TORRES, 1 MARIANA BORGES DIAS, 2 DELIO CAMPOLINA, 2 CARLOS CHAVEZ-OLORTEGUI 3 and CARLOS FARIA SANTOS AMARAL 1 1 School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil, 2 Joao XXIII Hospital, Belo Horizonte, Brazil, 3 FUNED, Belo Horizonte, Brazil; and 4 Department of Epidemiology (Visiting Scientist), Rollins School of Public Health, Emory University, 1518 Clifton Road, NE, Atlanta, GA 30322, U.S.A. (Received 21 January 1998; accepted 27 March 1998) Nilton Alves de Rezende, Felipe Maia Torres, Mariana Borges Dias, Delio Campolina, Carlos Chavez-Olortegui and Carlos Faria Santos Amaral. South American rattlesnake bite (Crotalus durissus sp) without envenoming: insights on diagnosis and treatment. Toxicon 36, 2029±2032, 1998.ÐA South American rattlesnake bite without clinical manifestations of envenoming (termed `dry-bite') has not been recognized to occur by the Brazilian Minis- try of Health, which recommends the administration of antivenom to all bit- ten patients. During 36 months of an observational study on South American rattlesnake bites in Minas Gerais, Brazil, 12% of 41 patients with fang marks at the bite-site did not present clinical or laboratory features of envenoming and had no plasma venom detected before speci®c serotherapy, ful®lling the criteria for the diagnosis of true `dry-bite'. Data from these pre- liminary observations suggest that these patients should be correctly diag- nosed since they should not be treated with unnecessary and sometimes hazardous and expensive serotherapy. # 1998 Elsevier Science Ltd. All rights reserved Although 20 to 50% of human snake bites do not result in systemic envenoming (Reid, 1968, 1970; Russell et al., 1997), the envenomed victims ®gure as an important public health problem throughout the world. In Brazil, the venomous South American Rattlesnake (Crotalus durissus sp) accounts for almost 10% of the 20,000 snakebites reported yearly, with a mortality rate of 1.5% in treated patients (Anonymous, 1996). Toxicon Vol. 36, No. 12, pp. 2029±2032, 1998 # 1998 Elsevier Science Ltd. All rights reserved Printed in Great Britain 0041-0101/98 $19.00 + 0.00 PII: S0041-0101(98)00112-3 * Author to whom correspondence should be addressed. 2029