Facial Epidermal Inclusion Cysts Are Associated with Smoking in Men: A Hospital-Based Case-Control Study

BACKGROUND Epidermal inclusion cysts (EICs) are a common cutaneous disorder in adults. The etiology of EICs remains obscure. Our clinical experience suggests that smoking may be a risk factor for the development of EICs. OBJECTIVE To determine whether the number and sites of EICs are related to smoking behavior and quantity. METHODS AND MATERIALS We retrospectively surveyed patients pathologically diagnosed with EICs at our hospital. A control group comprised patients who underwent surgical procedures for diagnoses other than EICs. Smoking history was obtained through telephone or clinical interviews. RESULTS Three hundred one patients with EICs were identified in our archives: 217 men (mean age 37.1, range 9-77) and 84 women (mean age 41.3, range 9-82). Detailed medical records and smoking history were available for 225 patients. Two hundred twenty-five age-and sex-matched patients were enrolled in the control group. Results showed that a higher percentage of men with facial EICs than of control subjects were smokers (p<.01). No such association was found in women with EICs. CONCLUSION Smoking may contribute to the development of EICs.