Spontaneous pneumomediastinum is defined as mediastinum gas that has not been caused by historical trauma or an underlying lung disease. Spontaneous pneumomediastinum can be diagnosed by a chest examination, a radiological examination, or when subcutaneous emphysema is found in the neck. The condition is rare among children and adolescents. Here, we describe a clinical case of spontaneous pneumomediastinum in a patient with no previous medical or trauma history. We discuss the pathogenesis, radiological findings, and clinical presentations of this condition in this patient. Finally, we provide recommendations concerning diagnostic modalities for spontaneous pneumomediastinum in younger patients.
A 17-year-old adolescent presented to the emergency department at our hospital complaining of acute onset chest pain. The patient had no previous medical or trauma history. A physical examination revealed a blood pressure of 135/80 mmHg, a pulse of 60 beats per minute, and a body temperature of 35.5o C. Subcutaneous emphysema was identified on the right side of the neck; however, the neck and chest were unaffected by local redness or tenderness. The patient did not present dyspnea.
A chest x-ray revealed the presence of air in the mediastinum, and chest computed tomography identified spontaneous pneumomediastinum. The patient was admitted to the inpatient ward, where he received conservative treatment. Symptoms resolved gradually, and the patient was discharged. Follow-up with the outpatient department was recommended.
Figure 1. Posteriorantero chest X-ray from the 17-year-old patient; subcutaneous emphysema and pneumomediastinum in the right neck are noted.
Figure 2. Chest CT scan revealing air in the mediastinum.
Spontaneous pneumomediastinum primarily affects adult males and is seldom observed in children or adolescents. The most common cause of this condition is air leaking through an alveolar rupture in the pulmonary interstitium. Many diseases and physiological events can lead to alveolar rupture. In children, the most common etiology of spontaneous pneumomediastinum is acute asthma exacerbation. Other causes include intense physical activity, coughing, vomiting, infection, the ingestion of a foreign body ingestion, or esophageal rupture. Clinical symptoms of spontaneous pneumomediastinum include chest pain (which may radiate to the neck, shoulders, and back), dyspnea, dysphagia, and subcutaneous emphysema. In severe cases, a distended neck vein can be observed due to the compression of venous return by air.
In cases where spontaneous pneumomediastinum is suspected, frontal and lateral chest radiographs should be arranged. Radiographic signs of spontaneous pneumomediastinum include gas outlining mediastinal structures or the lateral margin of the aorta. However, it should be noted that computer tomography is more sensitive than chest X-rays in the diagnosis of spontaneous penumomediastinum.
Simple spontaneous pneumomediastinum is typically addressed using conservative treatment including rest, pain control, and the avoidance of activities, which could increase pulmonary pressure. Therapy involving supplementary oxygen is also a treatment option.
Overall, spontaneous pneumomediastinum is a benign disease which can resolve after 2 to 14 days of conservative treatment. Chest computed tomography is a more sensitive diagnostic modality than a chest X-ray; however, it involves far greater exposure to radiation. A child exposed to high levels of radiation may face unknown complications in the future. Nonetheless, if the child has no history of trauma, serious medical problems, or underlying lung disease, then diagnosis through computed tomography may be advisable. The patient reported here presented stable vital signs, and a chest X-ray revealed signs indicative of spontaneous pneumomediastinum.We suggested that we can observe the patient vital sign instead of chest computed tomography; however, this would require detailed communication with the family about the timing of chest computed tomography .