Eruptive Vellus Hair Cysts in a Patient with Mental Retardation / 대한피부과학회지

ABSTRACT

Eruptive vellus hair cysts (EVHCs) are small, red- or brown-colored cystic papules that usually occur on the chest and proximal extremities of children and adults. Histologically, these small cysts are observed in the mid-dermis and contain multiple hair shafts and keratinous material. Pathogenesis of EVHC has not been completely understood. A 40-year-old man with mental retardation presented with multiple bluish papules on his back. A biopsy specimen showed features of eruptive vellus hair cysts. We report a case of EVHC that occurred at an unusual site in a patient with mental retardation.