Hyperkeratinization (

American English American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lang ...

or hyperkeratinisation in

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

) is a

disorder Disorder may refer to randomness, a lack of intelligible pattern, or: Healthcare * Disorder (medicine), a functional abnormality or disturbance * Mental disorder or psychological disorder, a psychological pattern associated with distress or disab ...

of the cells lining the inside of a

hair follicle The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction betwee ...

. It is the normal function of these cells to detach or slough off ( desquamate) from the skin lining at normal intervals. The dead cells are then forced out of the follicle (primarily by the growing hair). However, in hyperkeratinization, this process is interrupted and a number of these dead skin cells do not leave the follicle because of an excess of

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hoove ...

, a natural protein found in the skin. This excess of keratin, which is influenced by genetics, results in an increased adherence/bonding of dead skin cells together. This cohesion of cells will block or "cap" the hair follicle (leading to

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, goosefl ...

) or clog the

sebaceous A sebaceous gland or oil gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in t ...

/oil duct (leading to

acne Acne ( ), also known as ''acne vulgaris'', is a long-term Cutaneous condition, skin condition that occurs when Keratinocyte, dead skin cells and Sebum, oil from the skin clog hair follicles. Typical features of the condition include comedo, ...

). Pathogens may also play a role in causing, perpetuating, or simply taking advantage of this phenomenon, such as virulent sub-strains of ''

Cutibacterium acnes ''Cutibacterium acnes'' (''Propionibacterium acnes'') is the relatively slow-growing, typically aerotolerant anaerobic, gram-positive bacterium (rod) linked to the skin condition of acne; it can also cause chronic blepharitis and endophthalmitis ...

'' and irregular migration of ''

Staphylococcus epidermidis ''Staphylococcus epidermidis'' is a Gram-positive bacterium, and one of over 40 species belonging to the genus ''Staphylococcus''. It is part of the human flora, normal human microbiota, typically the skin flora, skin microbiota, and less commonl ...

'' from the outer surface of the skin into the follicle, where

commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit f ...

strains of ''C. acnes'' exclusively habitate. It itches mildly at times, and strongly at others. Very often it cannot be felt at all.

References

External links

{{Medical resources , ICD11 = {{ICD11, ED9Y , ICD10 = {{ICD10, L73.8 , ICD10CM = , ICD9 = , ICDO = , OMIM = , MeshID = , DiseasesDB = , SNOMED CT = , Curlie = , MedlinePlus = , eMedicineSubj = , eMedicineTopic = , PatientUK = , NCI = , GeneReviewsNBK = , GeneReviewsName = , NORD = , GARDNum = , GARDName = , RP = , AO = , WO = , OrthoInfo = , Orphanet = , Scholia = Q5958197 , OB = Dermatologic terminology

See also

References

Further reading

External links