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.
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.
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.Arch Dermatol. 1996;132:1481-1484
Kayashima K, Kitoh M, Ono T. Infantile Perianal Pyramidal Protrusion. Arch Dermatol. 1996;132(12):1481-1484. doi:10.1001/archderm.1996.03890360071012