Case History by Dr. William M. Simpson

A 14-year-old male was bitten on the dorsum of the foot when he put on a shin guard prior to a soccer game. He paid little attention to the bite, but did crush the spider that crawled out of the shin guard when he took it off. The shin guard had been in his open soccer bag that had been left in the attached garage of his home since a game two days earlier.

During his soccer game he developed pain in his groin, mild nausea, and cramping in his lower back and abdomen. He was able to complete his game, but the cramping worsened as the evening wore on. His mother, a registered nurse, treated him with diphenhydramine, ibuprofen, fluids and a warm bath. The bite site itself had the appearance of a bruise with a pale ring of skin around it. The teenager's symptoms improved and he slept through the night awakening with only residual muscle soreness. He was free of symptoms later in the day.

A county Extension agent referred the mother to the Agromedicine Program and she brought the spider to our office for identification. The specimen was partially crushed, but measured approximately 35mm in leg span. There was a pale hourglass mark on the ventral surface of the abdomen and several splotches of red on the dorsal side.

The specimen was a "widow spider" — probably Latrodectus variolus (the "northern black widow") — found from New England and adjacent Canada south to Florida and west to Texas, Oklahoma and Kansas. L. variolus is more common in the northern part of this range, but the markings on this spider would be unusual on the "standard" black widow — Latrodectus mactans. The size of the specimen was characteristic of a female adult. Females are usually 30-40mm across, males 15-20mm.

The warm bath might have made the symptoms worse since venom absorption is slowed by ice packs over the bite. Since the warm bath was hours after the bite, it probably had little effect. There are no effective first aid measures except for ice to reduce pain.

Treatments available for more severe cases include IV calcium gluconate, tetanus vaccine (if patient needs a booster), and Antivenin for very small children or elderly patients.

DEPARTMENT OF FAMILY MEDICINE – DIVISION OF PUBLIC HEALTH AND PUBLIC SERVICE

MEDICAL UNIVERSITY OF SOUTH CAROLINA, 171 ASHLEY AVENUE, CHARLESTON, SC 29425-2217