ABSTRACT
Infectious epidermal cyst (IEC) is one of the most common cutaneous cysts. It sometimes causes severe bacterial infection and requires incisional drainage under local anesthesia. We reviewed the short-term outcome of the severe IEC patients with the Japanese traditional medicine, hainosankyuto, instead of surgical drainage. We retrospectively examined 125 patients of IEC (52 males and 73 females) administered hainosankyuto (HST). No recurrence for a year after the inflammatory symptoms disappeared was defined as short-term cure. We compared the cure rate and the internal use period by gender, age, affected area, premedication of antibiotics, and complications of immunosuppressive therapy. Overall, 88 cases (70%) were short-term cured and the average oral administration was 14.6 days. There was no gender difference. In age-related analysis, the cure rate tended to be lower in the 30s-50s because of many dropouts. In the examination by site, the cure rate was significantly higher in the other site group (63/78 cases : 80%) than back and buttock group. The average oral administration period was longer in the back and buttock group, respectively. The cure rate was higher in the antibiotic premedication group. The average oral administration period was significantly shorter in the no premedication group. In immunosuppressive group, 21 of 24 patients (87.5%) were cured, which was significantly higher than normal group. There was no difference in average oral administration period between the two groups. Hainosankyuto treatment was beneficial for short-term cure of severe IEC.