According to a published case study1 in the Journal of Emergency Medicine, a teenager was admitted to the ER and diagnosed with pneumothorax, pneumomediastinum, and pneumoretropharyngeum after reportedly screaming intensely at a concert for boy band “One Direction.”
Pneumothorax is a lung collapse that occurs when air leaks into the space between the lung and chest wall.  Pneumomediastinum is air in the mediastinum (the space in the middle of the chest, between the lungs and around the heart).  Pneumoretropharyngeum (also known as retropharyngeal emphysema) is air in the space behind the pharynx. 
The case study reports that the girl, a 16-yr old with a history of type-1 diabetes, visited the emergency department with shortness of breath. Several noninvasive tests revealed nothing out of the ordinary, however, according to Live Science, doctors pressing down on the girl’s chest and neck said it created the sensation that they were crushing Rice Krispies beneath their fingers. 
After neck and chest x-rays, it was revealed the teen had “extensive subcutaneous emphysema in anterior neck and retropharyngeal space with associated pneumomediastinum and small bilateral pneumothoraces,” the journal article said.
According to the report, the girl reported sudden onset of dyspnea after “forceful screaming” at the concert the night before. CT scans could find no other underlying cause of the three conditions. Blood tests also revealed that the diabetes played no apparent role in the conditions.
Live Science reported that doctors could not determine an exact cause. She was admitted for observation, treated and released.