An etiology of anal fistula in infants.

Anal fistula in infants is considered to be not due to diaper dermatitis but it is developed in the process: hyperfunction of sebaceous glands induced by either excessive secretion of sex hormones (maternal hormones and hormones in the baby) or disorders related to hormones-acne vulgaris-fistula forma tion. Because the incidence of infantile anal fistula is very high in patients below the age of one month, the author recommends to put this fistula in the category of diseases of newborn babies, and to call it "fistula ani neonatorum". It is presumed that the fistula-in-ano which is usually observed in adult is also due to the abnormal development of pilo-sebaceous system or of free sebaceous glands (Fordyce's disease) of the anus. That is, the anal fistula in adults is pathogenically the same as that in infants. In addition, it is neces sary to reconsider the theory in which cryptoglands infection is regarded as the cause of anal fistula. Until recently fistula in infants has not been paid much attention, However, with its increased incidence in recent years, it is getting important. The author', a practitioner specializing in both dermatology and anal surgery who is supposed to be rare, has had chances to examine the anus, and has taken an interest in the anal fistula in infants, especially in its causes. An etiology of the anal fistula in infants has not been clarified basically while some people have the assumption of diaper dermatitis. This paper presents evi dences to draw the author's conclusion to make some contribution to the fistula etiology and controvert the hypothesis of diaper dermatitis. First, the incidence of anal fistula including periproctic abscess by age, from birth to childhood, was examined. In 1974, doctors2 in the Pediatric Surgery Sec tion of the Second Department of Surgery, Tokyo University School of Medicine, reported that 70% of 132 children with anal fistula consisted of infants under one year, especially in the early period of a few months. Two years ago, in