[Black widow spider (Latrodectus tredecimguttatus) bite. Presentation of 12 cases]

The most severe cases of arachnidism are those due to Latrodectus tredecimguttatus spider-bite. The Mediterranean area is the habitat of the L. tredecimguttatus species. In the last few years no series of patients with latrodectism has been reported in Spain. A retrospective study of the patients admitted for L. tredecimguttatus spider bite in the Torrecárdenas Hospital in Almeria, Spain from 1984 to 1994 was performed. Twelve patients were diagnosed with latrodectism. Eleven were bitten while carrying out agricultural tasks, 8 of which were performed in greenhouses. The mean time between the bite and the appearance of the general symptoms was 40 minutes (20-120 minutes), with the most common signs and symptoms being: pain and abdominal stiffness (10 cases), erythema (10 cases) or pain (8 cases) at the site of the bite, thoracic pain, pain in extremities and contractures and psychomotor alterations (6 cases). Laboratory findings were limited to leukocytosis (4 cases), increase in creatinphosphokinase count (4 cases) and proteinuria (3 cases). All the patients received analgesics, 6 were administered myorelaxants and calcium gluconate was given in 6 cases. The evolution was good without complications in all of the patients. Latrodectism is a rare phenomenon Spain. The diagnosis is difficult when there is absence of a clear history of spider bite and due to the lack of knowledge as to its semiology. Antivenom serum is not usually required.