Severe congenital ichthyosis is composed of heterogeneous subtypes, including bullous congenital ichthyosiform erythroderma (epidermolytic hyperkeratosis) (BCIE), harlequin ichthyosis (HI) and lamellar ichthyosis (LI). BCIE is a skin disease caused by mutations in the genes encoding keratins 1 and 10. Lamellar granules/filaggrin and keratinocyte transglutaminase, which is closely related to formation of the cornified cell envelope are suggested to be the candidate molecules for the pathogenesis in HI and LI, respectively. The purpose of the present study is to elucidate characteristic features of the structural protein expression seen in BCIE, HI and LI. Two patients with BCIE, two newborn babies with HI and a patient with LI were included in the present study. Immunohistochemical labeling revealed that keratins 5 and 14 were expressed normally in the basal cell layer and that keratins 1 and 10 were distributed in the suprabasal layers in the lesional skin of BCIE, HI and LI. The expression of filaggrin/profilaggrin was observed in the granular and the upper layers in all the cases. Abnormally dotted pattern of expression of keratin 1 and 10 were observed in the lesional skin of BCIE. These results suggest that the distributions of keratins and filaggrin/profilaggrin are normal in all LI, HI and BCIE, although the abnormal aggregations of keratin 1 and 10 are present in BCIE.