title: Infantile perianal pyramidal protrusion.
abstract: BACKGROUND
  The number of reported cases of infantile perianal eruption has been increasing. However, infantile pyramidal protrusion located in the midline anterior to the anus has apparently been reported mainly as acrochordons or skinfolds.
  
  
  METHODS
  Fifteen infants (14 girls and 1 boy) had a pyramidal protrusion located only in the midline anterior to the anus. Histological examination revealed acanthosis in the epidermis, marked edema in the upper dermis, and mild infiltrates in the dermis. The patients had been brought to the hospital because of swelling of the protrusion. However, all protrusions showed reduction without any treatment.
  
  
  CONCLUSIONS
  Infantile pyramidal protrusion located only in the midline anterior to the anus should be distinguished from acrochordons or skinfolds based on the characteristic clinical features.
authors.affiliation: Department of Dermatology, Kumamoto University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kayashima
authors.forename: M
authors.initials: M
authors.lastname: Kitoh
authors.forename: T
authors.initials: T
authors.lastname: Ono
mesh_terms: D001004:Anus Diseases / Q000473:pathology*; D002675:Child, Preschool; D004487:Edema / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D004912:Erythrocytes / Q000473:pathology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009504:Neutrophils / Q000473:pathology; D010502:Perineum / Q000473:pathology; D012871:Skin Diseases / Q000473:pathology*