ichthyosis bullosa of Siemens

an autosomal dominant condition caused by mutation in the KRT2 gene (locus: 12q11-q13), which encodes keratin 2e, characterized by mild blistering in infancy on skin surfaces that bump objects; the blisters shed to leave small areas denuded of stratum corneum. When this subsides, the child has hyperkeratosis of elbows, knees, and other joints.