Danazol therapy for cyclic thrombocytopenia

Cyclic thrombocytopenia is a rare disease characterized by cyclic oscillations of platelet counts from very low to normal or higher. Severe hemorrhage may occur during the thrombocytopenic phase. To date, treatments for this disorder have been disappointing. Its pathophysiology is unknown. We report a successful outcome using danazol therapy. It can be argued that the long‐term outcome was due to spontaneous remission. However, significant improvement was noted from the outset of danazol therapy, and further improvement with long‐term therapy, as seen in the response of chronic ITP to danazol therapy. Danazol may offer lasting benefit in cyclic thrombocytopenia.