A 12-Year-Old Girl Presenting With Recurrent Dyspnea and Pulmonary Ground-Glass Opacities.

A 12-year-old girl presented with shortness of breath with exercise for 2 weeks. Her oxygen saturation was 85% during exercise. Birth and family histories were unremarkable. The girl was healthy until 7.1 years of age, when she suffered a "pneumonia" with fever, dyspnea, and hypoxemia, which diminished after a 19-day treatment with antibiotics and methylprednisolone. These symptoms relapsed 8 months later, and she was diagnosed with rapidly progressive interstitial lung disease (ILD) and a Mycoplasma pneumoniae infection. At that time, her symptoms failed to respond to a course of antibiotic therapy but resolved with IV methylprednisolone at 2.7 mg/kg/day. She remained on a tapering dose of methylprednisolone plus methotrexate for the next 18 months until withdrawal of these medications because of return of almost normal lung imaging. She had never had myalgia, muscle weakness, arthritis, rashes, mechanic's hands, Raynaud's phenomenon, dry mouth, or dry eyes.