Dental Infection Mimicking Dermatological Lesion: Three Case Reports of Cutaneous Fistulae and Sinus Tracts on Face.

Cutaneous odontogenic fistulae or sinus tracts are commonly misdiagnosed and incorrectly treated, leading to unnecessary and excessive medications attributing to patient agony. An understanding of cutaneous sinus tracts and their drainage will guide to more appropriate treatment. The following clinical case reports present three patients with cutaneous sinus tracts on chin and jaw line, secondary to chronic periapical dental infection, which was misdiagnosed initially as dermatological lesion and was submitted to inappropriate dermatological treatment and antimicrobial therapy. Diagnosis, etiopathogenesis, and treatment in relation to patient history, clinical findings, and radiographic imaging are elaborated.

Introduction

Cutaneous fistulae are common clinical entities. Cutaneous sinuses of cervico-facial region comprise an important group of lesions, which may present to numerous specialties of medicine.[1] Possible odontogenic causes for such cutaneous lesions on cervico-facial region include trauma, retained roots, residual chronic infection of the jaws, and pulp disease.[2] It has been estimated that half of the patients with extraoral sinus are submitted to multiple dermatological surgeries and long-term antibiotic therapy[3] due to its similarity to various dermatologic conditions, coupled with the absence of dental signs and symptoms. These symptoms, however, are refractory to such procedures requiring dental therapy for their permanent resolution[4] and to avoid recurrence.[5] Till date, some cases have been reported in the literature, with very few cases highlighting broad and potential magnitude of cutaneous sinus and fistulas all over the mandibular jaw line on a single-article platform. The following comprehensive clinical reports present three patients with cutaneous sinus tract on chin and jaw line, secondary to chronic periapical dental infection in all three jaw regions (anterior, bicuspid, and molar regions) areas, which was misdiagnosed initially as a dermatological lesion and was submitted to inappropriate dermatological treatment and antimicrobial therapy.

Case report 1

A 20-year-old female patient reported to the dental outpatient department with chief complaint of intermittent pus discharge at the base of the chin since the past 3 years. No relevant medical history was reported. She denied the presence of any tooth pain or swelling. A history of trauma while playing at school, 4–5 years back, was elicited. Cutaneous draining lesion appeared 2 years after the accident. The patient reported to a nearby medical practitioner for an opinion, suspecting it to be a cancerous lesion. Subsequently, she received several courses of oral antibiotics, but did not get long-term relief. The ulcerative lesion kept recurring at regular intervals. Continuous foul smelling discharge led the patient to visit a dermatologist and an otorhinolaryngologist (ENT) specialist before being referred to the dental department. Extraoral examination revealed a cutaneous sinus of about 1 cm in diameter along the chin, with a red halo at the center [Figure 1a]. Palpation elicited purulent exudate from the sinus. Detailed intraoral examination revealed slightly discolored mandibular right central incisor tooth [Figure 1b]. No abnormalities such as swelling or carious teeth were noted. Pulp vitality tests were positive for all the mandibular incisors except for lower right central incisor. Panoramic radiograph revealed a well-defined unilocular, periapical lesion measuring around 2 cm × 4 cm in relation to these teeth. The well-defined margins of the lesion indicated a chronic, longstanding lesion such as a periapical cyst. A computed tomography scan was done, which displayed a radiolucency involving the cortical bone [Figure 1c]. Root canal treatment was initiated for the teeth in question. Mild exudate drained through the canal was sent to the microbiology department for bacterial culture and antibiotic sensitivity testing. Thorough cleaning and shaping of the canal was done, and calcium hydroxide (Metapex, Chungcheongbuk-do, Korea) was placed within the root canal as an intracanal medicament.

Figure 1

(a) Preoperative photograph of the extraoral cutaneous sinus on chin; (b) intraoral photograph showing the discolored mandibular right central incisor tooth; (c) computed tomography scan revealing radiolucency and fenestration defect involving the labial cortical bone in relation to apices of mandibular right central incisor tooth; (d) clinical presentation after 2 weeks Ca(OH)2 therapy; (e) postoperative photograph showing diminished extraoral fistula after 6 months recall

On 2 weeks recall, cutaneous sinus drainage ceased. Calcium hydroxide [Figure 1d] was removed, and an antibiotic paste was placed as intracanal medicament (paste of ciprofloxacin 500 mg and metronidazole 400 mg, 1:1 ratio) based on sensitivity testing of microbes within the pus sample.[45] The patient was recalled after 8 weeks, and extraoral sinus had resolved considerably. Canal obturation was performed by lateral condensation technique using gutta-percha (Dentsply, Maillefer, Switzerland) and AH26 sealer (Dentsply DeTrey, Germany). The patient was recalled at 6 and 12 months for check-up [Figure 1e]. At each visit, no recurrence of symptoms was reported, radiolucency grew progressively smaller, and the adjacent teeth gave a positive response to vitality testing.

Case report 2

A male patient age 22 years presented to the Department of Dentistry with a nodular swelling on the right side of his face since 3 years [Figure 2a]. Furthermore, he complained of occasional purulent discharge since 2 years. The patient had no significant medical history. History further revealed repeated occurrence of well-localized swelling in cheek, which reduced after bursting. The patient had experienced pain in the lower posterior tooth before swelling. Thorough history also revealed that he had visited a dermatologist for the same and was advised with medication, after which the lesion did not heal. The patient then visited a dentist who referred him to the institution for management of the same. When the patient was examined, he had tender nodular swelling on cheek. Routine blood investigations were performed before initiation of treatment. Diabetic and infective status (HIV and HbsAg tests) were checked to rule the immune-compromised status. Intraoral examination was remarkable for poor dentition and oral hygiene [Figure 2b]. A dental panoramic radiograph revealed diffuse radiolucency at the apex (consistent with a chronic periapical abscess) of supra-erupted, partially mobile and deeply carious mandibular right first molar [Figure 2c]. It was too late to be corrected with endodontic treatment; therefore, the tooth was extracted without complication. Dental sinus and extraoral nodule healed soon after treatment. Clinical follow-up at 6 months and 1 year revealed no complaints after treatment [Figure 2d].

Figure 2

(a) Preoperative photograph of the extraoral chronic nodule and draining sinus on the right side of the face; (b) preoperative intraoral photograph showing poor oral hygiene and supra-erupted, partially mobile and deeply carious mandibular right first molar; (c) panoramic radiograph demonstrating abscessed mandibular right first molar; (d) postoperative healed sinus and extraoral nodule after 1-year follow-up

Case report 3

A female patient age 30 years presented with a draining fistula on the cheek [Figure 3a]. Clinically, a draining lesion of approximately 1 cm diameter was noticed on the right cheek slightly above the inferior border of the mandible. The patient also complained of pain in right cheek, followed by light red discharge since 6 months. Dental examination revealed severe carious lesions on both the right mandibular bicuspids [Figure 3b], and panoramic radiograph showed abscess extending beyond the pulp and involving the periapical area rendering them clinically mobile [Figure 3c]. Gutta-percha cone was inserted into the sinus tract and gently pushed inside until there was no resistance. An intraoral periapical radiographic view showed the tip of the gutta-percha cone to be close to the lesion. These teeth were all diagnosed to be non-restorable and were noted for diagnosis of periapical abscess with a guarded prognosis. The patient was referred to oral and maxillofacial surgery for extraction. The extraction procedure was routine and the patient was lost to follow-up.

Figure 3

(a) Preoperative photograph of cutaneous draining sinus tract on right cheek region; (b) preoperative intraoral examination revealing severe carious lesions on both the right mandibular bicuspids; (c) panoramic radiograph demonstrating periapical radiolucency and deep carious lesions associated with right mandibular premolars

Discussion

Odontogenic cutaneous lesion is characterized by the presence of a draining sinus fistula originating from a localized area with pus and surrounded by granulation tissue in alveolar bone of the affected tooth. The majority of odontogenic sinus fistulas have an intraoral opening,[6] but in cases of chronic dental infection, local inflammatory destructive process progresses slowly as an alveolar bone abscess. Once the inflammation passes through cortical bone and periosteum, it may spread into the surrounding soft tissue, limited by muscle attachments and facial regions. The periapical and periodontal infections arising from mandibular anterior teeth produce cutaneous sinuses if their roots lie below the origin of mentalis muscle or roots are long. Those arising from premolar teeth produce sinuses rarely over the mandible after piercing the triangularis and quadrate muscles of the lower lip. Those arising from mandibular molars produce sinuses if their roots lie below the buccinator muscle on the buccal side or below the attachment of the mylohyoid muscle on the lingual side producing sinuses on the buccal and lingual sides of the mandible, respectively.[7] In the three cases described here, cutaneous sinuses arising from anterior teeth, bicuspids, and molar teeth were reported. Endodontic therapy is certainly the most appropriate non-surgical therapy for treating dental abscesses or periapical lesions. It was carried out in three visits without antibiotics in the first case. However, in other two cases presented, the teeth were beyond restorable and endodontic intervention was not appropriate. In all three of these cases, the infections were successfully treated with endodontic treatment or tooth extraction therapy and healing was uneventful. One patient was lost to follow-up. We consider this to be a positive outcome to the treatment provided, because we believe that a patient who experiences a problem with treatment is more likely, not less likely, to return for a follow-up visit.

Skin manifestations of odontogenic cutaneous sinus fistulas are nonspecific and have rarely been mentioned in the literature. The orifice of a cutaneous sinus fistula can present as a dimpling, nodule, abscess, cyst, ulcer, draining lesion, or nodulocystic lesion with suppuration.[8] Moreover, the variable location of odontogenic cutaneous fistula is the main cause of diagnostic confusion, although locations are related to affected teeth. Notably, misdiagnoses have also been reported in edentulous patients with fistulas resulting from infected implants, bones, or bone grafts.[9] The differential diagnosis reported in literature review includes subcutaneous mycosis and neoplastic processes, such as squamous cell carcinoma, basal cell carcinoma, and pyogenic and foreign body granolumas.[8] Diagnostic errors lead to multiple trials of antibiotics and unnecessary repeat surgical procedures. When a lesion develops, being unaware of its dental origin, patients seek treatment from dermatologists or surgeons. Lack of dental examination possibly leads to inappropriate treatments.[9] Intraoral and dental examination and panoramic view X-ray imaging are critical for diagnosis.[6] Another important diagnostic modality is the determination about the nature of fluid draining from cutaneous sinus. In all the three cases reported here, an attempt was made to milk the sinus tract during palpation. Cultural and antibiotic sensitivity of the fluid was performed to rule out fungal and syphilitic infection. Infections were found to be polymicrobial, and culture yielded growth of anaerobes or facultative anaerobes, like streptococcus species. Administration of systemic antibiotic based on cultural sensitivity may result in temporary reduction of the drainage and apparent healing. However, permanent cure was obtained after proper dental treatment, such as extraction or endodontic therapy, leading to lesion resolution. Dimpling and hyperpigmentation of the skin usually diminish slowly, and sometimes it remains on the face as a small dimple. Thus, surgical revision or fistulectomy may be needed in some cases for esthetic reasons.[10]

Conclusion

The variable characteristics of odontogenic cutaneous fistulas lead to diagnostic confusion. This case series illustrates that dental infections of the oral cavity can present with a well-localized abscess away from the causative site. Odontogenic cutaneous sinus fistulas should always be considered in differential diagnosis of tumors and chronic facial lesions that recur despite treatment. Attending clinicians should carefully take patient history, understand anatomy of the region, and examine the possibility of a potential odontogenic infection. The basic keys to making a correct diagnosis are chronicity (weeks, months, or even years) of the lesion and the recognition that facial lesion can be related to a tooth by a sinus or fistula. Extraoral and intraoral examinations are critical to achieve a diagnosis of odontogenic cutaneous fistula, and thus, mutual cooperation between dermatologists or surgeons and dentists is quintessential.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.