Keratosis (from ''
kerat-'' + ''
-osis'')
is a growth of
keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...
on the skin or on
mucous membrane
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...
s stemming from
keratinocyte
Keratinocytes are the primary type of Cell (biology), cell found in the epidermis (skin), epidermis, the outermost layer of the skin. In humans, they constitute 90% of epidermal skin cells.
Basal cells in the stratum basale, basal layer (''str ...
s, the prominent cell type in the
epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...
. More specifically, it can refer to:
*
actinic keratosis
Actinic keratosis (AK), sometimes called solar keratosis or senile keratosis, is a pre-cancerous area of thick, scaly, or crusty skin.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . Actinic k ...
(also known as solar keratosis), a
premalignant condition
A precancerous condition is a condition, tumor or lesion involving abnormal cells which are associated with an increased risk of developing into cancer. Clinically, precancerous conditions encompass a variety of abnormal tissues with an increased ...
*
chronic scar keratosis
A chronic scar keratosis is a precancerous skin lesion that arises within a long-standing scar
A scar (or scar tissue) is an area of fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wo ...
*
hydrocarbon keratosis A hydrocarbon keratosis (also known as "pitch keratosis", "tar keratosis", and "tar wart") is a precancerous keratotic skin lesion that occurs in people who have been occupationally exposed to polycyclic aromatic hydrocarbon
A polycyclic aromat ...
*
keratosis pilaris
Keratosis pilaris (KP; also follicular keratosis, lichen pilaris, or colloquially chicken skin) is a common, autosomal- dominant, genetic condition of the skin's hair follicles characterized by the appearance of possibly itchy, small, goosefle ...
(KP, also known as follicular keratosis)
*
seborrheic keratosis
A seborrheic keratosis is a non-cancerous (benign) skin tumour that originates from cells, namely keratinocytes, in the outer layer of the skin called the epidermis. Like liver spots, seborrheic keratoses are seen more often as people age.
The tum ...
, ''not'' premalignant
See also
*
Folliculitis
Folliculitis is the infection and inflammation of one or more hair follicles. The condition may occur anywhere on hair-covered skin. The rash may appear as pimples that come to white tips on the face, chest, back, arms, legs, buttocks, or head.
A ...
*
Keratoderma
Keratoderma is a hornlike skin condition.
Classification
The keratodermas are classified into the following subgroups:Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. .
Congenital
* Simple ker ...
References
External links
Dermatologic terminology
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