Chapter 2 covers Ichthyoses (Bullous Congenital Ichthyosiform Erythroderma, Harlequin Ichthyosis, Ichthyosis Bullosa of Siemens, Ichthyosis Hystrix, Ichthyosis Vulgaris, Lamellar Exfoliation of the Newborn, Lamellar Ichthyosis/Nonbullous Congenital Ichthyosiform Erythroderma, Netherton Syndrome, Peeling Skin Syndrome, Restrictive Dermopathy, and X-linked Recessive Ichthyosis), Erythrokeratodermas (Erythrokeratodermia Variabilis ET PROGESSIVA, and Pityriasis Rubra Pilaris), Acrokeratoderma (Acrokeratoelastoidosis, Acrokeratosis Verruciformis (HOPF)), Hereditary Palmoplantar Keratodermas (Hereditary Palmoplantar Keratoderma with Deafness, Hereditary Palmoplantar Keratoderma Epidermolytic Hyperkeratosis, Hereditary Palmoplantar Keratoderma Howel-Evans, Hereditary Palmoplantar Keratoderma Olmsted, Hereditary Palmoplantar Keratoderma Punctate, Hereditary Palmoplantar Keratoderma Striata, Hereditary Palmoplantar Keratoderma Unna-Thost, Hereditary Palmoplantar Keratoderma Vohwinkel, Keratolytic Winter Erythema, Mal de Meleda, Papillon-Lefèvre, Scleroatrophic and Keratotic Dermatosis of the Limbs), Porokeratoses (Porokeratosis of Mibelli), Other Disorders of the Epidermis (Absence of Dermatoglyphics, Acanthosis Nigricans, Darier-White Disease, Hereditary Painful Callosities, Keratosis Follicularis Spinulosa Decalvans, Knuckle Pads, Kyrle/Flegel Disease, Ulerythema Ophryogenes), Syndromic Disorders (CHILD Syndrome, Chondrodysplasia Punctata, Ichthyosis with Hypogonadism, KID Syndrome, Neu-Laxova Syndrome, Neutral Lipid Storage Disease with Ichthyosis, Refsum Disease, Richner-Hanhart Syndrome, Sjögren-Larsson Syndrome), Cohesion (Epidermolysis Bullosa, Epidermolysis Bullosa Simplex Dowling-Meara, Epidermolysis Bullosa Simplex Generalized, Epidermolysis Bullosa Simplex Localized, Epidermolysis Bullosa Junctional Generalized, Epidermolysis Bullosa Junctional Generalized Atrophic Benign, Epidermolysis Bullosa Dystrophica Cockayne-Touraine, Epidermolysis Bullosa Dystrophica, Hallopeau-Siemens, Epidermolysis Bullosa Dystrophica Pretibial, Transient Bullous Dermolysis of the Newborn, Hailey-Hailey Disease). Each condition is discussed in detail, including dermatologic features, associated anomalies, histopathology, basic defect, treatment, mode of inheritance, prenatal diagnosis, and differential diagnosis.