Also found in: Dictionary, Thesaurus, Acronyms, Encyclopedia, Wikipedia.
any horny growth, such as a wart or callosity.
actinic keratosis a sharply outlined wartlike or keratotic growth, which may develop into a cutaneous horn, and may become malignant; it usually occurs in the middle aged or elderly and is due to excessive exposure to the sun. Called also senile or solar keratosis. (See Atlas 3, Part F).
keratosis follicula´ris a slowly progressive autosomal dominant disorder of keratinization characterized by pinkish to tan or skin-colored papules on the seborrheic areas of the body that coalesce to form plaques, which may become crusted and secondarily infected; over time, the lesions may become darker and may fuse to form papillomatous and warty malodorous growths. Called also Darier's disease and Darier-White disease.
keratosis palma´ris et planta´ris palmoplantar keratoderma.
keratosis pharyn´gea horny projections from the tonsils and pharyngeal walls. Called also pharyngokeratosis.
keratosis pila´ris hyperkeratosis limited to the hair follicles.
keratosis puncta´ta a hereditary hyperkeratosis in which the lesions are localized in multiple points on the palms and soles.
seborrheic keratosis (keratosis seborrhe´ica) a benign, noninvasive tumor of epidermal origin, marked by numerous yellow or brown, sharply marginated, oval, raised lesions.
senile keratosis (solar keratosis) actinic keratosis.
a premalignant warty lesion occurring on the sun-exposed skin of the face or hands in aged light-skinned persons; hyperkeratosis may form a cutaneous horn, and squamous cell carcinoma of low-grade malignancy may develop in a small proportion of untreated patients.
a slowly developing, localized thickening and scaling of the outer layers of the skin as a result of chronic, prolonged exposure to the sun. It is more common in the fair skinned and elderly. It usually is a discrete, slightly raised, red-on-pink lesion located on a sun-exposed surface. Treatment of this premalignant lesion includes surgical excision, cryotherapy, and topical chemotherapy. Also called senile keratosis, senile wart, solar keratosis.
actinic keratosisA premalignant lesion of sun-exposed skin that is overly sensitive to the effects of UV light (i.e., sunlight), and more common in the fair-skinned or elderly, and the immunocompromised.
Cryosurgery, photodynamic therapy, laser (CO2, Er:YAG), electrocautery; some topical immune response modifiers (e.g., 5FU) may be used to promote peeling.
± 20% of AKs develop into squamous cell carcinoma.
Broad-spectrum sunscreens with a sun protection factor of 17 may reduce new lesions; avoid photosensitising drugs (e.g., tetracyclines); in subjects with AK placed on a low-fat diet, the incidence of new lesions fell to 1⁄3 that of the control (non-diet intervention) group. HPV replication is thought to play a role in malignant changes.
actinic keratosisSenile keratosis, solar keratosis Dermatology A premalignant lesion of sun-exposed skin that is overly sensitive to the effects of UV light–sunlight, and more common in the fair-skinned or elderly Clinical Discrete scaly or gritty erythematous plaques located on a sun exposed surface Diagnosis Biopsy Management Cryosurgery or electrocautery; some topicals may be used to promote peeling Prognosis ± 20% of AKs develop into SCC Prevention Broad-spectrum sunscreens with a sun protection factor of 17 may ↓ new lesions; avoid photosensitizing drugs–eg, tetracyclines. See Squamous cell carcinoma.
ac·tin·ic ker·a·to·sis(ak-tin'ik ker'ă-tō'sis)
A premalignant warty lesion occurring on the sun-exposed skin of the face or hands in aged light-skinned people; hyperkeratosis may form a cutaneous horn, and squamous cell carcinoma of low-grade malignancy may develop in a small proportion of untreated patients. Treatment includes cryotherapy, surgical excision, or topical chemotherapy.
actinic keratosisAbbreviation: AK
A rough, sandpaper-textured, premalignant macule or papule caused by excess exposure to ultraviolet light. AKs often appear on facial skin (such as near the eyes, on the nose, on the ears, or the lips) and the parts of the body that receive the most sunlight exposure. Prevention of AKs depends on limiting one's exposure to sunlight, beginning in childhood and continuing throughout life. See: illustrationSynonym: solar keratosis See: sunscreen
Liquid nitrogen destroys these lesions and prevents them from progressing to other cancers of the skin.
See also: keratosis
actinic keratosisLocal overgrowth and thickening of the EPIDERMIS of the skin caused by sunlight. This condition can progress to a form of skin cancer (SQUAMOUS CELL CARCINOMA) and is usually treated by freezing.
A crusty, scaly pre-cancerous skin lesion caused by damage from the sun. Frequently treated with cryotherapy.
ac·tin·ic ker·a·to·sis(ak-tin'ik ker'ă-tō'sis)
A premalignant warty lesion occurring on the sun-exposed skin of the face or hands in aged light-skinned people.
any horny growth on the skin, such as a wart or callosity; a firm, elevated, circumscribed area of excessive keratin production. Common in humans but uncommon in animals.
varies from a sharply outlined verrucous or keratotic growth to poorly defined areas of erythema, which are premalignant lesions. Due to excessive exposure to the sun. Called also solar keratosis.
equine cannon keratosis
see cannon keratosis.
see equine linear keratosis.
hyperkeratosis limited to the hair follicles.
seborrheic keratosis, keratosis seborrheica
single or multiple elevated plaques and nodules often hyperpigmented with a hyperkeratotic greasy surface. They are benign, of unknown etiology, but have no connection with seborrhea. Occur in dogs and humans.
see actinic keratosis (above).