Abstract： A 2-month-old baby girl developed universal keratotic plaques soon after birth. Physical examination revealed well-defined, dark erythematous, keratotic plaques with thick scales and mild infiltration at the periorbital, perioral, perianal and vulvar regions, as well as deep fissures of both hands and feet covered with thick yellowish crusts. Another case was a 24-year-old female, the mother of the baby, who presented with hyperkeratotic plaques at perioral and perianal regions, congenital alopecia universalis, mutilation of fingers and toes with massive thick keratotic yellow crusts and scales. Histopathology of skin lesions from the gluteal region of the baby showed psoriasiform hyperplasia of the epidermis, slight inflammatory infiltration of dermal papillae and superficial dermal perivascular regions. Immunohistochemistry demonstrated the positive staining for acidic keratin (AE1) in the prickle cell layer and granular layer and for CK10 in the upper prickle cell layer and granular layer. Electron microscopy showed increased cell space and decreased tonofilament. Both the baby girl and her mother were diagnosed with Olmsted syndrome.