A survey of 234 cases of pemphigus yielded three observations which suggest that different forms of pemphigus may have different etiologies.
1. While the incidence of pemphigus in the age group of 21 and over was essentially the same in males and females (108 and 113) the incidence was significantly higher in females in the age group under 20. Only two of 13 patients in this group were males. Also pemphigus foliaceus and erythematosus was reported in a significantly higher proportion of the cases in the age group of 2 1/2 to 20 thus suggesting that the juvenile form of the discase differs from the adult form.
2. In four of a group of 15 cases identified as pemphigus foliaceus the disease appeared to be provoked by minor physical insults, a frequency which is significantly higher than the five cases with similar histories in the group of 198 cases identified as pemphigus vulgaris.
3. In the entire group of 234 cases two patients with pemphigus both proven by immunofluorescence had relatives with pemphigus. Also a third patient had a blood relative with bullous pemphigoid. This frequency of three per 234 is higher than would be expected by chance. Studies of one family (not included in this survey) with multiple skin antibodies suggest that such familial predispositions may be due to abnormal immune responses.