epidermolytic hyperkeratosis

hyperkeratosis /hy·per·ker·a·to·sis/ (-ker″ah-to´sis)

1. hypertrophy of the stratum corneum of the skin, or any disease so characterized.

2. hypertrophy of the cornea.

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epidermolytic hyperkeratosis  a hereditary disease, with hyperkeratosis, blisters, and erythema; at birth the skin is entirely covered with thick, horny, armorlike plates that are soon shed, leaving a raw surface on which scales then reform.

hyperkeratosis follicula´ris in cu´tem pe´netrans  Kyrle's disease.

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epidermolytic hyperkeratosis

Etymology: Gk, epi + derma, skin + lysis, loosening; Gk, hyper, excess + keras, horn + osis, condition

a rare autosomal-dominant form of ichthyosis with a high frequency of spontaneous mutations. Present at birth, it is characterized by generalized erythroderma and severe hyperkeratosis with small wartlike scales over the entire body, especially in body folds, and sometimes on the palms and soles. There are also recurrent bullae on the lower limbs. If sepsis and electrolyte imbalances are not treated correctly in neonates, morbidity can occur. Also called bullous congenital ichthyosiform erythroderma. See also ichthyosis.

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hyperkeratosis [hi″per-ker″ah-to´sis]

1. hypertrophy of the horny layer of the skin, or any disease characterized by it.

2. hypertrophy of the cornea. adj., adj hyperkeratot´ic.

epidermolytic hyperkeratosis a hereditary autosomal dominant form of ichthyosis, present at birth. Characteristics include generalized redness of the skin and severe hyperkeratosis with small, hard wartlike scales over the entire body, accentuated in areas that flex or bend and sometimes involving the palms and soles. In infancy and childhood, there are recurrent bullae, most often on the lower limbs.

follicular hyperkeratosis a skin condition characterized by excessive development of keratin in hair follicles, resulting in rough, cone-shaped, elevated papules, the openings of which are often closed with a white plug of encrusted sebum. Deficiencies of vitamins A and E, B complex vitamins, and essential fatty acids have all been implicated in the etiology. Called also phrynoderma.

hyperkeratosis lenticula´ris per´stans an autosomal dominant skin disorder, usually occurring in the third or fourth decade of life, characterized by pink, red, or yellow to brown scaly papules on the lower leg and back of the foot, and sometimes on the trunk, thigh, arm, back and palm of the hand, or sole of the foot.

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hyperkeratosis

1. hypertrophy of the horny layer (stratum corneum) of the skin, or any disease characterized by it; the hyperkeratoses may have distinctive formats, e.g. annular (ring formations), basket-weave, compact, laminated.

2. hypertrophy of the cornea.

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bovine hyperkeratosis

chlorinated naphthalene poisoning.

digital hyperkeratosis

increased thickness of the keratinized epidermis of footpads in dogs and rarely cats. May be in response to trauma or associated with distemper (hardpad disease), or pemphigus foliaceus.

epidermolytic hyperkeratosis

a form of ichthyosis in humans which is inherited as an autosomal dominant trait; there is severe degeneration of the granular layer of the epidermis.

juvenile hyperkeratosis

a crusting dermatosis over bony prominences, face and chin of young dogs. See zinc-responsive dermatosis.

nasal hyperkeratosis

an abnormal thickening, sometimes with fissures, of the planum nasale of dogs. May occur in association with digital hyperkeratosis (see above) as a feature of distemper (hardpad disease). Also seen in pemphigus foliaceus and discoid lupus erythematosus.

Nasal hyperkeratosis. By permission from Kummel BA, Color Atlas of Small Animal Dermatology, Mosby, 1989

nasodigital hyperkeratosis

see nasal hyperkeratosis, digital hyperkeratosis (above).

orthokeratotic hyperkeratosis

hyperkeratosis with non-nucleated cells present.

parakeratotic hyperkeratosis

hyperkeratosis with nucleated cells present; called also parakeratosis.