Asthmatic versus non-asthmatic spontaneous pneumomediastinum in children

The aim of this study was to analyze the clinical spectrum and seek potential curable causes of spontaneous pneumomediastinum (SPM) in children in order to minimize respiratory morbidity. Medical records from 1986 to 2003 were retrospectively reviewed at a tertiary pediatric facility in northern Taiwan. Sixteen cases of SPM were identified. There were eleven boys and five girls (M:F = 2.2:1) and ages ranged from 2 to 17 years (average, 10 years). Cough (81%), dyspnea (75%) and chest pain (56%) were the predominant symptoms and expiratory wheezing (63%) and neck crepitus (50%) were the most common physical findings. The specific sign of Hamman's crunch was noted in only one child initially. A coughing-related Valsalva maneuver (13 patients/81%) was the most common cause of pneumomediastinum in these children. The most common underlying medical causes were asthma (8 patients/50%) and idiopathic origin (5 patients/31%). Acute gastroenteritis, foreign body aspiration and mycoplasmal pneumonia were each found in one patient respectively. All patients had subcutaneous emphysema on initial chest radiographs. Two patients were complicated by pneumothorax and required intensive respiratory therapy. The average hospital stay was 4 days (range 1-9 days). Rapid resolution of symptoms without long-term sequelae was common except for one patient who had hypoxic-ischemic encephalopathy with epilepsy after foreign body removal. We conclude that in young teenagers, who suffer from cough, dyspnea, chest pain and associated discomfort of throat or neck, the diagnosis of SPM should be considered and chest radiography including posterior-anterior and lateral projections should be performed to verify the diagnosis. Because of the high prevalence of asthma related SPM, children of idiopathic SPM should undergo diagnostic pulmonary function tests after the acute episode, to establish whether the child has asthma. Targeted investigations of the underlying causes of SPM might decrease respiratory morbidity and avoid further complications.