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Hypertrophy of the cornea.
Hypertrophy of the horny layer of the skin.



excessive development of the corneous layer of the skin in humans. Hyperkeratosis may be caused by external factors (such as prolonged pressure, friction, or the effects of lubricating oils) or internal factors (endocrine dysfunctions, hypovitaminosis A, occupational intoxication). Hyperkeratosis is manifested by the formation of horny plates, nodes of various sizes, protuberances, and spurs; the skin becomes dry and perspiration decreases. Hyperkeratosis may be accompanied by the formation of painful cracks (on the palms and soles). It may be limited (calluses, warts, keratomas) or diffuse, spread over large areas or the entire skin surface (ichthyosis). Treatment consists in soda or soap baths, vitamin therapy, and medications that dissolve the horny substance.

References in periodicals archive ?
2008) demonstrated that exposed individuals with hyperkeratosis have significantly higher DNA damage (measured by a chromosomal aberration assay in lymphocytes) and less DNA repair capacity (measured using a challenge assay in whole blood) than those without skin lesions.
DiGiovanna JJ, Bale SJ: Clinical heterogeneity in epidermolytic hyperkeratosis.
Papillon-Lefevre syndrome (PLS) is a rare autosomal recessive disorder presented with diffuse transgradient palmoplantar hyperkeratosis, and an aggressive periodontal inflammation leading to premature loss of primary and permanent teeth.
Hyperkeratosis, acantholysis, dyskeratosis, and suprabasilar clefts were also focally present.
Ulceration, as well as foci of hyperkeratosis (thickening of the stratum corneum), may be seen within the areas of atrophy.
Sun-exposed epidermis becomes thickened as much as twofold compared to sun-protected skin and is disorganized, showing evidence of hyperkeratosis, parakeratosis, and acanthosis.
Some patients have had hyperkeratosis, psoriasis and eczema.
In this study, the most common adverse reactions (greater than or equal to 10%) of any grade for dabrafenib included hyperkeratosis (thickening of the outer layer of the skin)(37%), headache (32%), pyrexia (fever)(28%), arthralgia (joint aches)(27%), papilloma (warts)(27%), alopecia (hair loss)(22%), palmar-plantar erythrodysesthesia (redness, swelling, peeling or tenderness of hands or feet)(20%), rash (17%), back pain (12%), cough (12%), myalgia (muscle aches)(11%), constipation (11%) and nasopharyngitis (cold-like symptoms)(10%).
Mild mucosal hyperplasia and hyperkeratosis were observed within the crop, consistent with crop stasis, and the koilin layer was degenerative within the ventriculus.
Human exposure to inorganic arsenic, a potent oxidative stressor, causes various dermal disorders, including hyperkeratosis and skin cancer.
1-3,6) Other findings include hyperkeratosis and parakeratosis, pseudoepitheliomatous hyperplasia of the epidermis, and hyperplastic lymphoid tissue.
Histologic findings consist of hyperkeratosis, acanthosis and marked decrease in dermal elastic fibers.