The victim may not be aware of being bitten for an hour or more, or a painful reaction may occur almost immediately. A stinging sensation is followed by intense pain. A small white blister usually develops at the site of the bite. The affected area enlarges, swells, and the tissue is hard to the touch. This tissue is killed and eventually sloughs away, leaving a sunken, ulcerated sore.
Healing takes place slowly, requiring six to eight weeks.
Skin grafts may be needed for complete recovery, and even then large scars may remain. Most encounters with brown recluses occur at night when the spiders are foraging for food. Others occur when seldom-used clothes are put on again and contain a spider. Brown recluse spiders cannot bite humans without some form of counterpressure to assist, such as occurs when they are trapped and held against the skin. Medical attention should be obtained as soon as possible after the bite occurs.