Etiologies of spontaneous pneumomediastinum in children of different ages.

BACKGROUND: Spontaneous pneumomediastinum (SPM), while rare, is probably underestimated in children. Treatments for SPM target the underlying disease and trigger factors. This study aimed to analyze the etiology of SPM in different age groups.

METHODS: A total of 18 children with SPM were analyzed in the Children's Medical Center at China Medical University Hospital between 1997 and 2007.

RESULTS: The incidence of SPM in children was 1:8,302 patients at the Department of Pediatric Emergency Medicine. A bimodal peak in incidence occurred in those younger than 4 years old and in those aged 15-18 years. Characteristic symptoms were dyspnea (77.8%), followed by chest pain (66.7%) and neck pain (44.4%); common specific physical signs were subcutaneous emphysema (55.6%) and Hammer's sign (11.1%). Trigger factors were infection (44.4%), with a mean age of 5.8+5.0 years, and diabetic ketoacidosis (5.6%), with a mean age of 18 years. Idiopathic SPM accounted for 50.0% of patients, with mean age 14.4 +/- 1.8 years. In terms of the age distribution, five (27.8%; males/females=4:1) preschoolers (<6 years old) developed SPM, mostly due to infectious disease. Two girls aged less than 10 years developed asthma in later years. All eight male adolescents (> or =10 years) developed SPM due to idiopathic factors. Of nine boys with idiopathic SPM, six underwent strenuous exercise before developing SPM. Mean hospitalization was 7.9 +/- 11.5 days and 11 (61.1%) patients needed intensive care. Nearly all of the patients had complete resolution on chest radiography before discharge.

CONCLUSION: Clinicians should be alert to the risk of SPM based on the presence of these symptoms. The etiology of SPM varies with age. Treatment of SPM must target the trigger factors or the underlying disease.