You can identify this spider by the red hourglass marking on its belly. At first you may notice only slight swelling and faint red marks. Within a few hours, though, intense pain and stiffness begin. The bite produces a mild stinging, followed by local redness and intense pain within 8 hours. A fluid-filled blister forms at the site and then sloughs off to leave a deep, growing ulcer.
Reactions vary from a mild fever and rash to nausea and listlessness.
On rare occasions death results. Apply a cool compress over the bite location and keep the affected limb elevated to about heart level. Do not give aspirin to children. Give them acetaminophen instead. Treatment in a medical facility may be necessary for children less than 6 years old or for adults with severe symptoms.