[Seborrheic dermatitis and cancer of the upper respiratory and digestive tracts].

Seborrheic dermatitis (SD) is frequent in adults. Its aetiology is unknown, and the alleged causative effect of Pityrosporum-type yeasts is strongly controverted. Nutritional, genetic and neuropsychological factors may play a part in its occurrence. The responsibility of immunological factors has recently been illustrated by the high prevalence of SD in patients with acquired immunodeficiency syndrome. We found a high frequency of SD in patients under treatment for carcinomas of the upper respiratory and digestive tracts (URDT), and in order to confirm this finding we carried out a prospective case-control epidemiological study. Since most patients with URDT carcinoma are heavy drinkers and smokers, we divided our controls into two groups: chronic alcoholics without cancer (Group B) and patients with non-URDT cancers. At the time of admission, all patients were examined by the same physician, and SD was diagnosed on clinical grounds. Cases (Group A) comprised 50 patients (48 men, 2 women; mean age 56 years) with URDT carcinoma. All were alcohol and tobacco addicts. Thirty-six of these patients had undergone surgery for their cancer, and among these 19 had received radiotherapy, 8 chemotherapy and 18 both chemo- and radiotherapy. The first control group (Group B) also comprised 50 patients, all male, with a mean age of 59 years, who had been admitted for diseases due to alcoholism but showed no evidence of cancer. The second control group (Group C) consisted of 50 male patients (mean age 69 years) whose cancer was not an URDT carcinoma.(ABSTRACT TRUNCATED AT 250 WORDS)