Supplemental table 1. Keratoacanthoma patients under observation without treatment
From January 2005 to December 2020, a total of 81 patients were diagnosed with keratocanthoma (KA) at our center (Seoul national university hospital). Observations were made on 7 out of 81 patients. Among 7 patients, except 4 patients lost to followup, 3 patients experienced complete remission which took 20, 33, and 40 weeks, respectively.