Chronic dental periapical infections or dentoalveolar abscesses cause the most common intraoral and extraoral fistulas. These dental periapical infections can lead to chronic osteomyelitis, cellulitis, and facial abscesses. Infection can spread to the skin if it is the path of least resistance. Fascial-plane infections, space infections, and osteomyelitis can cause cutaneous fistulas. Fascial-plane infections often begin as cellulitis and progress to fluctuant abscess formation. Compared with the other conditions, fluctuant abscess formation is more likely to result in cutaneous fistulas.
Rarely, a cutaneous lesion such as a furuncle can be misdiagnosed as a sinus tract to the skin of the face. One case report[1] demonstrates this occurrence from a periapical infection from the right central mandibular incisor, which drained to the patient’s chin. Because the tooth could not be restored, it was extracted, which resolved the lesion.
Another case with cutaneous manifestations involved a 44-year-old woman with a draining lesion to the skin just lateral to the nasofacial sulcus. Oral antibiotics did not help resolve the lesion. The patient had poor dentition, and a panoramic radiograph showed 2 periapical radiolucencies of the maxillary right lateral incisor and canine. The teeth were extracted, which resolved the lesion. Sheehan et al[2] recommend a dental examination and radiographs to rule out infection of dental origin to the cutaneous face or neck.
