Propylthiouracil-induced organizing pneumonia: A case report.

Rationale: Propylthiouracil (PTU) is a common antithyroid drug which can treat hyperthyroidism effectively. PTU is, however, associated to multiple adverse effects. In rare case, PTU can cause interstitial pneumonia.

Patient Concerns: A 40-year-old woman presented with dyspnea and was diagnosed with pulmonary infection at the first time. After the treatment with moxifloxacin, her symptoms still got worse.

Diagnosis: The lung tissues biopsy confirmed the diagnosis of organizing pneumonia (OP) and the administration of PTU suggested the diagnosis of PTU-induced OP.

Intervention: Withdrawal of PTU and the administration of methylprednisolone.

Outcomes: The patient's symptoms relieved significantly 1 month later and lung computed tomography (CT) scan also demonstrated significant reduction of lung lesions.

Lessons: Here we report the first case of histologically confirmed OP induced by PTU and conduct a literature review of the cases of PTU-induced interstitial pneumonia. The awareness of PTU-induced OP can help physicians reduce the possibility of misdiagnosis.