A Rare Case of Severe Burn Injury to the Oropharynx Caused by a Flare Gun

SUMMARY

Flare gun injuries are rare, and patients often present with complex trauma that may require multiple operative interventions. Our objective is to explore a case of a 15-year-old male, who presented with second-degree flame burns to the face, left upper extremity and bilateral hands, as well as third-degree burns to the oropharynx and a tongue laceration after a flare gun was discharged into his mouth. The patient underwent multiple debridements of the oral cavity and oropharynx, and his hospital course was complicated by an intra-oral abscess. He eventually made a full recovery and was discharged. This case not only illustrates the need for early operative intervention, but it also underscores the need for awareness campaigns that highlight the dangers of flare guns and similar devices.

Introduction

Flare gun injuries are rare and have only been reported sporadically in literature. Most flare guns currently on the market contain numerous compounds, including magnesium, strontium nitrate, strontium peroxide and potassium perchlorate.^1,2 Flares have been used for distress signaling, illumination and defensive countermeasures in civilian and military applications.² When discharged, the components within the flare ignite at 191°C and can burn up to 1,600°C.³ Although incidents involving flare guns, fireworks and similar devices remain infrequent, if they do occur, patients often present with extensive soft tissue trauma complicated by burns, foreign bodies, fractures and lacerations, which ultimately may require multiple operative interventions.⁴ The United States Consumer Product Safety Commission (CPSC) estimates that over 10,500 individuals were treated in hospitals for fireworks-related injuries in 2014. Individuals younger than 20 years comprised nearly half of the group, and most injuries involved the hands, face and eyes. The CPSC’s National Electronic Surveillance System (NEISS) also found that children aged 10 to 19 years had the highest rate of injury, which were mainly caused by firecrackers and aerial devices.⁵ This report explores a case of severe burns to the oral cavity and oropharynx secondary to a flare gun and reviews the complex management of such an injury.

Case presentation

A 15-year-old male with no prior medical history was transferred from a referring facility to our burn center following an incident where a flare gun was discharged into his mouth. This event occurred while the patient was playing around with a friend. The patient was intubated at the outside facility prior to transfer due to drooling and suspected upper airway swelling. On admission to our burn center, he was noted to have second-degree flame burns to the face, left upper extremity (LUE) and bilateral hands, as well as third-degree burns to the oral cavity and oropharynx. A laceration of the tongue and fractures of the anterior maxillary teeth were also noted. Soot was present within the patient’s oral cavity. A bronchoscopy was performed, which demonstrated serosanguineous drainage, but no soot within the lungs. Imaging obtained on admission included a computed tomography (CT) scan of the head, neck and the maxillofacial area, which confirmed a soft tissue defect of the dorsal surface of the tongue extending to the genioglossus muscle. The patient was evaluated by otolaryngology and a direct laryngoscopy was performed, which demonstrated diffuse burns to the hard palate, tongue and posterior pharyngeal wall. The uvula was edematous and there was a 1 x 2 cm midline dorsal tongue defect (Fig. 1). A feeding tube was placed shortly after admission for administering tube feeds.

Fig. 1.

Through-and-through laceration of the tongue

The patient underwent multiple procedures during his hospitalization, including tracheostomy, debridement of the lips, buccal mucosa, floor of the mouth and tongue, and incision and drainage of a tongue abscess. Significant necrotic tissue and adhesions were noted within the oral cavity; however, this improved over time with repeated debridements. An esophagoscopy during the initial operation demonstrated mild mucosal circumferential burns to the esophagus. The patient also underwent debridement of the dorsal and palmar surfaces of his hands bilaterally followed by application of Suprathel (PolyMedics Innovations GmbH, Denkendorf, Germany). A laparoscopic gastrostomy tube was placed by the Pediatric Surgery team.

Although the patient was on intravenous (IV) ampicillin-sublactam, he was persistently febrile. Given the suspicion for aspiration on admission, there was some concern for pneumonia and the patient was started on IV cefepime, metronidazole and vancomycin. Additionally, intra-operative cultures of the oropharyngeal wounds were found to be growing methicillin-sensitive Staphylococcus aureus (MSSA) and Streptococcus agalacticae. Blood cultures remained negative. As the patient continued to improve, he was gradually transitioned to tracheostomy collar trials, which he tolerated well. He was eventually decannulated and did not have any additional respiratory issues.

Prior to discharge, the patient was evaluated by Speech Therapy and a modified barium swallow study was completed. He was advanced to a pureed diet, which he tolerated well. The patient was on minimal anxiolytics and pain medications at the time of discharge.

On subsequent follow-ups, he continued to improve. There was no significant tethering of the tongue, and the base had healed fully with only slight circumferential narrowing. The patient was eating a regular diet by that time, and his gastrostomy tube was removed by Pediatric Surgery. His facial and upper extremity burns had healed well, and he was making appropriate progress.

Discussion

Severe flare gun-related injuries that require prolonged hospitalization are rare, and there is very limited literature dealing specifically with injuries of the oral cavity and oropharynx. One of the earliest cases of injuries caused by a flare gun was reported by Stevenson and Thomson in 1984.⁶ Their case focused on the management of full thickness burns to the glabella and nose, as well as an underlying fracture of the frontal region between the orbits in a 2-year-old female. The closest equivalent to the type of injuries that our patient suffered was a case of a 25-year-old female patient who sustained oropharyngeal burns due to spontaneous combustion of a lithium-ion battery in a flashlight.⁷

When dealing with intra-oral thermal injuries, a potential major complication is inhalation injury.⁸ The degree of inhalation injury can be variable and depends on the components inhaled, the presence of particulate matter, the magnitude of exposure, and other factors such as underlying lung disease or inability to flee the incident quickly.⁹ Pertinent physical findings include facial burns, singed facial or nasal hair, soot or carbonaceous material on the face or in the sputum, and signs of airway obstruction including stridor, edema, or mucosal damage.⁸ In the case of our patient, the burn injury was limited to the supraglottic airways without inhalation injury as confirmed by bronchoscopy.

Another important consideration when managing perioral or intra-oral thermal injuries is the potential for scarring that could lead to formation of contractures. Based on current literature, perioral burns involving the interior of the mouth rather than the commissure or lips have a better healing tendency as the blood supply of the oral mucosa is very rich and provides an ideal condition for healing.⁸ The severity of injury and the severity of the sequalae depends on the type of injury and the duration of exposure. Scar contractures can ultimately result in microstomia, tongue ankylosis, speech impairment, and problems with facial expressions.¹⁰ In our case, a conservative approach was taken in terms of management and involved debriding all necrotic tissue, followed by serial assessments for potential formation of scarring and contractures.

In terms of managing tongue lacerations, the major concerns with such injuries include hemorrhage, loss of function, infection, and edema that compromises the airway. The tongue has a rich blood supply, and thus, injuries to the tongue or the floor of the mouth may cause serious hemorrhage that may threaten the airway. Reconstruction of a laceration may not be required and wound healing can occur rapidly.¹¹ In our case, we allowed for healing of the patient’s tongue laceration by secondary intention, and on subsequent exams, the base of the tongue had healed fully with only slight circumferential narrowing. Generally, recommendations in literature regarding closure of tongue lacerations vary significantly, with some suggesting suturing both dorsal and lateral border injuries, while others have suggested loosely suturing tongue wounds and placing deep sutures in layers. Lacerations larger than 2 cm or those with difficulties in obtaining hemostasis require closure.¹¹

Conclusion

Flare gun injuries are rare; however, when they do occur, they can be devastating for the patient and management can be challenging. Despite the severity of some of these injuries, few publications exist that specifically examine the potential complications associated with an intra-oral flare gun discharge. It is imperative to understand and discuss these types of injuries because of the potential morbidities that may result.