Described since 1939 in the adult population, spontaneous pneumomediastinum is less known in children. Because of its symptoms and a generally benign evolution, it is probably an underestimated diagnosis. However, it has to be considered in the differential diagnosis of acute thoracic pain.
The incidence being low, we conducted a narrative literature review to identify the circumstances leading to a spontaneous pneumomediastinum, the most relevant signs and symptoms, investigations, as well as treatment recommendations.
Of 216 patients, 66.2% are boys, and mean ages range from 6.9 to 14 years. The most frequent comorbidity in children is asthma (22.2%), and the most common trigger factors are bronchospasm (49%), cough (45.6%), various respiratory tract infections, vomiting (10.3%), and foreign body aspiration (8.3%). It remains idiopathic in 33.3%. Relevant signs are chest pain (54.6%), neck pain and/or sore throat (53.3%), and dyspnea (41.2%). The most relevant sign is palpation of subcutaneous emphysema (66.4%). The classically described Hamman crunch is only present in 11.6%. Chest x-ray provides the right diagnosis in 99.5% of the patients. Pneumothorax is associated in 11.6%. Most patients are hospitalized (88.3%); treatment is based on oxygen therapy, painkillers, and rest. In some series, there can be up to 25.8% of patients requiring intensive care and 5.5% requiring drainage of associated pneumothorax. Survival rate is 92.5%, and long-term follow-up shows normal x-rays after 4 days and no recurrence.
Spontaneous pneumomediastinum is uncommon in children but must be considered in pediatric patients with acute chest and/or neck pain. History taking, physical examination, and standard chest x-ray are most often diagnostic, and there is rarely a need for other investigation.Hospitalization is not always indispensable; ambulatory management can be considered. Outcome is good, and follow-up can be clinical, therefore avoiding further x-rays.