U.S. Department of Defense


Date of this Version



Published in J Oral Maxillofac Surg 63:1774-1778, 2005.


Oral and maxillofacial surgeons must be prepared to manage a variety of maxillofacial infections, both odontogenic and non-odontogenic in nature. While odontogenic infections are quite common, non-odontogenic infections can present with diagnostic and therapeutic challenges. An uncommon non-odontogenic infection is the cellulitis secondary to a spider bite.
Few spider species have the ability to bite through human skin. Most of these insults result in only a small, red nodule centered within a larger, erythematous plaque. Symptoms are usually limited to pruritus and perhaps mild tenderness. The brown recluse and the black widow are 2 types of spiders that inhabit the United States that can cause serious injury or major medical problems to their victim. The bite of the brown recluse spider (Loxosceles reclusa) results in an envenomation that can have deleterious effects on the patient.
Within 6 hours after the bite, pain and erythema develop at the site. The area of erythema spreads during the first 24 hours and may turn bluish-purple. Necrosis of the skin often occurs 24 to 48 hours later. Signs include bullae formation, cyanosis, and hyperesthesia. Depending on their size, complete resolution of these lesions can take from weeks to months. Systemic symptoms include fever, chills, malaise, vomiting, and arthralgias. Less common but more severe reactions to the venom have resulted in hemolytic anemia, convulsions, renal failure, shock, disseminated intravascular coagulation, and rarely, death.
Brown recluse spider bites usually occur on the extremities or the trunk, but bites to the face have been reported. Treatment of a brown recluse spider bite is controversial and ranges from conservative comfort measures including rest, ice compresses, and elevation, to drug therapy and surgical excision.