OSTEOMYELITIS

Background:
Brown recluse spider bites cause significant trauma via their tissue toxic venom. Diagnosis of these injuries and envenomation is difficult and many times presumptive. Treatment is varied and dependent upon presentation and course of injury.

Materials and Methods:
We present a case of a previously unreported incidence of osteomyelitis of the mandible as a result of a brown recluse spider bite. A review of the literature and discussion of diagnosis and treatment of brown recluse spider bites are presented.

Results:
Osteomyelitis of the mandible causing a chronic wound was the presenting finding of a patient with a history of spider bite and exposure to brown recluse spiders. Operative debridement and wound closure resulted in successful treatment. Brown recluse spider envenomation varies in its presentation and treatment is based on the presenting clinical picture. Conclusion: Treatment regimens for brown recluse spider bite envenomation should include the basics of wound care. Systemic antibiotics, topical antimicrobials, dapsone, and surgical debridement are valuable adjuncts of treatment, as indicated, based on the clinical course.

Brown recluse spider bite envenomation can be a significant traumatic injury. Probably overreported, brown recluse spider bites and their resultant tissue injury patterns are well documented; however, treatment regimens are somewhat controversial. We present an unusual case of a presumed brown recluse spider bite injury of the face, which developed into chronic osteomyelitis of the mandible, and discuss the evaluation and further management of this interesting clinical presentation.

CASE REPORT

A 52-year-old white male presented with a 6-month history of a tender, open wound in the submental area. The chronic wound had been draining serous and purulent material for 4 to 6 weeks prior to evaluation. The wound began as a “pimple” on his chin that progressed in a few days to erythema, skin breakdown, and then, eventually, purulent drainage. The patient related a history of having encountered multiple “fiddleback” spiders at his place of work. He also claimed to have suffered multiple spider bites on the extremities in the past, all of which healed without sequelae. Physical examination was significant for a 5-mm open wound of the mandible, slightly to the right of the midline of his chin (Fig 1). The area was tender and a small amount of murky fluid was expressed. The wound probed to bone, using a sterile hemostatic clamp. There was no palpable regional lymphadenopathy. Computed tomography revealed a large bony cavity eroding through the inferior cortex of the mandibular symphysis anteriorly and abutting the lingual cortex. The mandibular integrity was intact with no evidence, clinically or radiographically, of a pathological fracture (Fig 2). The bony destruction appeared chronic, as evidenced by the sclerotic margins of the cavity. Differential diagnosis included possible odontogenic infection, neoplastic process, and traumatic wound infection. An odontogenic infection was excluded because of the viability of associated dentition and lack of demonstrable dental pathology. As a soft tissue or bony neoplasm appeared unlikely because of the smooth, sclerotic margins seen on computed tomographic scan and the lack of a demonstrable soft tissue lesion, this was attributed most likely to a wound infection secondary to traumatic injury.

Operative debridement was planned with a presumptive diagnosis of traumatic infection. The patient underwent excision of the wound and the chronic granulation/soft tissue inflammatory reaction within the bony cavity. The bone cavity was aggressively curetted and debrided to healthy bleeding bone (Fig 3). The mandibular symphysis was found to be extremely stable with adequate stock of bone to maintain its integrity without the need for mechanical reinforcement, either by plating or bone graft. The soft tissue was extensively mobilized and reapproximated in layers. The pathology report revealed chronic osteomyelitis. At 6 weeks follow-up, the wound had healed without complication or further sequelae (Fig 4).