Recurrent Spontaneous Pneumomediastinum in an Adolescent Competitive Swimmer: A Case Report.

Spontaneous pneumomediastinum (SPM) is a rare, usually self-limited condition in children and adolescents. Sports-related cases are generally considered benign, with early return to play often recommended. However, evidence to guide management in athletes who rely heavily on breath-holding, such as competitive swimmers, is limited. We report a 14-year-old male competitive swimmer who experienced three episodes of SPM over seven months. His initial presentation involved acute anterior chest pain with stable vital signs and mediastinal emphysema on CT. He improved with conservative treatment and returned to full training within one month, avoiding intense breath-holding for two weeks. A second presumptive episode occurred four months later, followed by a third episode three months after that, again with mediastinal emphysema on imaging. We hypothesized that persistent local tissue vulnerability, possibly incomplete healing of prior microinjury, together with rapid resumption of breath-hold training, contributed to recurrence. After the third episode, all training was restricted for two months, during which he completed supervised stretching and diaphragmatic breathing rehabilitation, followed by a gradual return to swimming while avoiding prolonged breath-holding. He has remained free of recurrent SPM. This case suggests that athletes who perform intense breath-holding may require more prolonged activity restriction, targeted respiratory rehabilitation, and explicit limitations on breath-holding to reduce the risk of SPM recurrence.