Encounters with people or animals are usually accidental and occur around the home or garage. Pain, resulting from the bite, is felt almost immediately and increases in intensity, reaching a maximum in 1 to 3 hours and continuing for up to 48 hours. Rigidity and spasms of most large muscle groups, particularly those of the abdomen, are common symptoms. There is usually a slight rise in body temperature, increased blood pressure, a leucocytosis, and an increase in spinal fluid pressure. The patient often becomes dizzy, weak, thirsty, nauseated and shows symptoms of shock.
Local treatment is generally ineffective and incision and suction are of little value.
Cortisone has also been reported to provide some relief. Mortalities are generally low. It can be recognized by the dark brown fiddle-shaped marking on the dorsal cephalothorax. The bite of this spider is localized and produces considerable necrosis which may lead to an unsightly scar. The necrotic area turns black and dry and may slough in a few days, leaving a granular area.