A 7-year-old girl with subcutaneous emphysema, pneumomediastinum, pneumothorax, and pneumoretroperitoneum caused by Mycoplasma pneumoniae pneumonia.

A 7-year-old girl presented with subcutaneous emphysema, pneumomediastinum (PM), pneumoretroperitoneum, and pneumothorax caused by Mycoplasma pneumoniae (MP). The patient had been treated with clarithromycin for pneumonia at another hospital; however, her condition deteriorated and complications developed. Soon after admission to our hospital, we started the patient on minocycline and prednisolone, and the complications improved promptly. Laboratory data showed serum ferritin and urinary beta-2-microglobulin levels were greatly elevated. We therefore speculated that the patient might have underlying hypercytokinemia. Prednisolone is an effective treatment for hypercytokinemia. We therefore recommend prednisolone treatment for cases of severe M. pneumoniae pneumonia that do not respond to antimicrobial agents.