The Arizona species is not the same as the brown recluse spider in the Midwest. The bite of the brown spider is a serious medical condition. The bite is nonhealing and causes tissue death. Sometimes surgery is necessary. The bite causes only a mild stinging sensation if any at all.
Victims often are unaware they have been bitten.
A blister appears surrounded by mild swelling and redness. The target lesion will enlarge over the next few days and produce extensive tissue death. There is no antivenom. The lesion will have to be soaked in antispetic and possibly antibiotics. Surgery may be necessary to cut out the dead tissue.