Pulmonary sarcoidosis: A novel sequelae of drug reaction with eosinophilia and systemic symptoms: A case report.

Background: Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is an uncommon yet serious adverse drug hypersensitivity reaction with the presentations including rash, fever, lymphadenopathy, and internal organ involvement. Sarcoidosis is a systematic granulomatous disease with unknown etiology. We herein report a case of pulmonary sarcoidosis secondary to allopurinol-induced DRESS.

Case Summary: A 37-year-old man with a history of hyperuricemia was treated with allopurinol for three weeks at a total dose of 7000 milligrams before developing symptoms including anorexia, fever, erythematous rash, and elevated transaminase. The patient was diagnosed with DRESS and was treated with prednisone for 6 mo until all the symptoms completely resolved. Three months later, the patient presented again because of a progressively worsening dry cough. His chest computed tomography images showed bilateral lung parenchyma involvement with lymph node enlargement, which was confirmed to be nonnecrotizing granuloma by pathological examination. Based on radiologic and pathological findings, he was diagnosed with sarcoidosis and was restarted on treatment with prednisone, which was continued for another 6 mo. Reexamination of chest imaging revealed complete resolution of parenchymal lung lesions and a significant reduction in the size of the mediastinal and hilar lymph nodes. Following a 6-month follow-up of completion of treatment, the patient's clinical condition remained stable with no clinical evidence of relapse.

Conclusion: This is the first case in which pulmonary sarcoidosis developed as a late complication of allopurinol-induced DRESS. The case indicated that the autoimmune reaction of DRESS may play an important role in the pathogenesis of sarcoidosis.