Hyperkeratosis
| Hyperkeratosis | |
|---|---|
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| Micrographshowing prominent hyperkeratosis in skin withoutatypia.H&E stain. | |
| Pronunciation | |
| Specialty | Dermatology |
Hyperkeratosisis thickening of thestratum corneum(the outermost layer of theepidermis,orskin), often associated with the presence of an abnormal quantity ofkeratin,[1]and is usually accompanied by an increase in the granular layer. As the corneum layer normally varies greatly in thickness in different sites, some experience is needed to assess minor degrees of hyperkeratosis.
It can be caused byvitamin A deficiencyor chronic exposure toarsenic.
Hyperkeratosis can also be caused byB-Rafinhibitor drugs such asVemurafenibandDabrafenib.[2]
It can be treated withurea-containing creams,which dissolve theintercellular matrixof the cells of the stratum corneum, promotingdesquamationof scaly skin, eventually resulting in softening of hyperkeratotic areas.[3]
Types
[edit]Follicular
[edit]Follicular hyperkeratosis, also known askeratosis pilaris(KP), is a skin condition characterized by excessive development ofkeratininhair follicles,resulting in rough, cone-shaped, elevatedpapules.The openings are often closed with a white plug of encrustedsebum.When calledphrynoderma,the condition is associated with nutritional deficiency or malnourishment.
This condition has been shown in several small-scale studies to respond well to supplementation with vitamins and fats rich inessential fatty acids.Deficienciesofvitamin E,[4]vitamin A,andB-complex vitaminshave been implicated in causing the condition.[5]Follicular hyperkeratosis is also a symptom in inherited collagen-related diseases ofEhlers-Danlos syndromesandBethlem myopathy.
By other specific site
[edit]- Plantar hyperkeratosisis hyperkeratosis of thesoleof thefoot.It is recommended to surgically remove the dead skin, to provide symptomatic relief.
- Hyperkeratosis of the nipple and areolais an uncommon benign, asymptomatic, acquired condition of unknown pathogenesis.[6]: 636
Hereditary
[edit]- Epidermolytic hyperkeratosis(also known as "Bullous congenital ichthyosiform erythroderma,"[7]"Bullous ichthyosiform erythroderma,"[8]: 482 or "bullous congenital ichthyosiform erythroderma ofBrocq"[9]) is a rare skin disease in theichthyosisfamily, affecting around 1 in 250,000 people. It involves the clumping ofkeratinfilaments.[6]: 562 [10]
- Multiple minute digitate hyperkeratosis,a rare cutaneous condition, with about half of cases being familial
- Focal acral hyperkeratosis(also known as "Acrokeratoelastoidosis lichenoides," ) is a late-onsetkeratoderma,inherited as anautosomal dominantcondition, characterized by oval or polygonal crateriformpapulesdeveloping along the border of the hands, feet, and wrists.[8]: 509
- Keratosis pilarisappears similar to gooseflesh, is usually asymptomatic and may be treated by moisturizing the skin.[11]
Other
[edit]- Hyperkeratosis lenticularis perstans(also known as "Flegel's disease"[7]) is a cutaneous condition characterized by rough, yellow-brown keratotic, flat-toppedpapules.[6]: 639 [7]
In mucous membranes
[edit]The term hyperkeratosis is often used in connection with lesions of themucous membranes,such asleukoplakia.Because of the differences between mucous membranes and the skin (e.g., keratinizing mucosa does not have astratum lucidumand non keratinizing mucosa does not have this layer or normally astratum corneumor astratum granulosum), sometimes specialized texts give slightly different definitions of hyperkeratosis in the context of mucosae. Examples are "an excessive formation of keratin (e.g., as seen in leukoplakia)"[12]and "an increase in the thickness of the keratin layer of the epithelium, or the presence of such a layer in a site where none would normally be expected."[13]
Etymology and pronunciation
[edit]The wordhyperkeratosis(/ˌhaɪpərˌkɛrəˈtoʊsɪs/) is based on theAncient Greek morphemeshyper-+kerato-+-osis,meaning 'the condition of too much keratin'.
Hyperkeratosis in dogs
[edit]Nasodigitic hyperkeratosis in dogs may be idiopathic, secondary to an underlying disease, or due to congenital abnormalities in the normal anatomy of the nose and fingertips.
In the case of congenital anatomical abnormalities, contact between the affected area and rubbing surfaces is impaired. It is roughly the same with finger pads — in animals with an anatomical abnormality, part of the pad is not in contact with rubbing surfaces and excessive keratin deposition is formed. The idiopathic form of nasodigitic hyperkeratosis in dogs develops from unknown causes and is more common in older animals (senile form).[14][15]Of all dog breeds, Labradors, Golden Retrievers, Cocker Spaniels, Irish Terriers, Bordeaux Dogs are the most prone to hyperkeratosis.[16]
Therapy
[edit]Since the deposition of excess keratin cannot be stopped, therapy is aimed at softening and removing it. For moderate to severe cases, the affected areas should be hydrated (moisturised) with warm water or compresses for 5-10 minutes. Softening preparations are then applied once a day until the excess keratin is removed.
In dogs with severe hyperkeratosis and a significant excess of keratin, it is removed with scissors or a blade. After proper instructions, pet owners are able to perform this procedure at home, and it may be the only method of correction.[17]
See also
[edit]References
[edit]- ^Kumar, Vinay; Fausto, Nelso; Abbas, Abul (2004)Robbins & Cotran Pathologic Basis of Disease(7th ed.). Saunders. Page 1230.ISBN0-7216-0187-1.
- ^Niezgoda, Anna; Niezgoda, Piotr; Czajkowski, Rafal (2015)Novel Approaches to Treatment of Advanced Melanoma: A Review of Targeted Therapy and ImmunotherapyBioMed Research International
- ^drugs > Urea Cream (Prescribing Information)Revised: 04/2010 by Stratus Pharmaceuticals
- ^Nadiger, HA (1980)."Role of vitamin E in the aetiology of phrynoderma (follicular hyperkeratosis) and its interrelationship with B-complex vitamins".British Journal of Nutrition.44(3): 211–4.doi:10.1079/bjn19800033.PMID7437404.
- ^"Hyperkeratosis".Dorland's Medical Dictionary for Health Consumers.2007.
- ^abcJames, William D.; Berger, Timothy G.; Elston, Dirk M.; et al. (2006). "Clinical diagnosis by laboratory methods".Andrews' diseases of the skin: clinical dermatology(10th ed.). Saunders Elsevier.ISBN0-7216-2921-0.
- ^abcRapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007).Dermatology: 2-Volume Set.St. Louis: Mosby.ISBN978-1-4160-2999-1.
- ^abFreedberg, et al. (2003).Fitzpatrick's Dermatology in General Medicine.(6th ed.). McGraw-Hill.ISBN0-07-138076-0.
- ^synd/1036atWho Named It?
- ^Cheng J, Syder AJ, Yu QC, Letai A, Paller AS, Fuchs E (September 1992). "The genetic basis of epidermolytic hyperkeratosis: a disorder of differentiation-specific epidermal keratin genes".Cell.70(5): 811–9.doi:10.1016/0092-8674(92)90314-3.PMID1381287.S2CID31906051.
- ^Hwang, Schwartz (Sep 2008). "Keratosis pilaris: a common follicular hyperkeratosis".Cutis.82(3): 177–80.PMID18856156.
- ^Mosby's Dental Dictionary
- ^Tyldesley WR, Field A, Longman L (2003).Tyldesley's Oral medicine(5th ed.). Oxford: Oxford University Press.ISBN0192631470.
- ^"Muller and Kirk's Small Animal Dermatology. Saunders, St. Luis, MO".scholar.google.RetrievedDecember 16,2021.
- ^"Skin diseases of the dog and cat: clinical and histopathologic diagnosis".scholar.google.RetrievedDecember 16,2021.
- ^"What Does it Mean When a Dog's Nose is Dry? When to Worry".boneandyarn.8 August 2020.RetrievedDecember 16,2021.
- ^"Hyperkeratosis In Dogs: Does Your Dog Have Hairy Feet?".caninejournal.7 January 2016.RetrievedDecember 16,2021.
External links
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