[Spontaneous pneumomediastinum initially interpreted as anaphylaxis in a boy]

Spontaneous pneumomediastinum is a rare but maybe also underdiagnosed condition in the paediatric population. Symptoms are often mild, and the disease course is often benign, but more serious differential diagnosis must be excluded. This case report is about a four-year-old boy admitted to the children's department with a suspected allergic reaction because off swelling of his chin after taking NSAID. He had pain from the throat and neck and crepitation on the left side of his thorax. X-ray showed pneumomediastinum and subcutaneous emphysema.