Monday 1 August 2016

Candida dandruff, no more Head and Shoulders

Dandruff

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For the album by Ivor Cutler, see Dandruff (album).
Dandruff
Dandruff01.jpg
A microscopic image of human dandruff
Classification and external resources
SpecialtyDermatology
ICD-9-CM690.18
DiseasesDB11911
MeSHD063807
Dandruff is the shedding of dead skin cells from the scalp.[1] As skin cells die, a small amount of flaking is normal; about 487,000 cells/cm2 get released normally after detergent treatment.[2] Some people, however, experience an unusually large amount of flaking either chronically or as a result of certain triggers, up to 800,000 cells/cm2, which can also be accompanied by redness and irritation.
Dandruff is a common scalp disorder affecting almost half of the population at the post-pubertal age and of any sex and ethnicity. It often causes itching. It has been well established that keratinocytes play a key role in the expression and generation of immunological reactions during dandruff formation. The severity of dandruff may fluctuate with season as it often worsens in winter.[2] Dandruff is rare before puberty, peaks in the teens and early twenties, and declines with age thereafter.[3] Most cases of dandruff can be easily treated with specialized shampoos. There is, however, no true cure.[4]
Those affected by dandruff find that it can cause social or self-esteem problems, indicating treatment for both psychological and physiological reasons.[5]


Signs and symptoms[edit]

Severe dryness of scalp resulting in Dandruff.
Typical case of dandruff.
The signs and symptoms of dandruff are an itchy scalp and flakiness.[6] Red and greasy patches of skin and feeling tingly on the skin are also symptoms.[7]

Causes[edit]

Dandruff can have several causes, including dry skin, seborrhoeic dermatitis, not cleaning/scrubbing often enough, shampooing too often, psoriasis, eczema, sensitivity to hair care products, or a yeast-like fungus.[8] Dry skin is the most common cause of flaking dandruff.[8]
As the epidermal layer continually replaces itself, cells are pushed outward where they eventually die and flake off. For most individuals, these flakes of skin are too small to be visible. However, certain conditions cause cell turnover to be unusually rapid, especially in the scalp. It is hypothesized that for people with dandruff, skin cells may mature and be shed in 2–7 days, as opposed to around a month in people without dandruff. The result is that dead skin cells are shed in large, oily clumps, which appear as white or grayish patches on the scalp, skin and clothes.
According to one study, dandruff has been shown to possibly be the result of three factors:[9]
  1. Skin oil commonly referred to as sebum or sebaceous secretions[10]
  2. The metabolic by-products of skin micro-organisms (most specifically Malassezia yeasts)[11][12][13][14][15]
  3. Individual susceptibility and allergy sensitivity.

Micro organisms[edit]

According to 2016 study bacteria (mainly Propionibacterium and Staphylococcus) are more important to dandruff formation than fungi. Bacteria presence was in turn influenced by water and sebum amount.[16]
Older literature cites the fungus Malassezia furfur (previously known as Pityrosporum ovale) as the cause of dandruff. While this species does occur naturally on the skin surface of both healthy people and those with dandruff, in 2007 it was discovered that the responsible agent is a scalp specific fungus, Malassezia globosa,[17] that metabolizes triglycerides present in sebum by the expression of lipase, resulting in a lipid byproduct oleic acid (OA). During dandruff, the levels of Malassezia increase by 1.5 to 2 times its normal level.[2] Penetration by OA of the top layer of the epidermis, the stratum corneum, results in an inflammatory response in susceptible persons which disturbs homeostasis and results in erratic cleavage of stratum corneum cells.[13]

Seborrhoeic dermatitis[edit]

In seborrhoeic dermatitis redness and itching frequently occur around the folds of the nose and eyebrow areas, not just the scalp. Dry, thick, well-defined lesions consisting of large, silvery scales may be traced to the less common affliction of the scalp psoriasis.
Inflammation and extension of scaling outside the scalp exclude the diagnosis of dandruff from seborrhoeic dermatitis.[10] However, many reports suggest a clear link between the two clinical entities - the mildest form of the clinical presentation of seborrhoeic dermatitis as dandruff, where the inflammation is minimal and remain subclinical.[18][19]
Seasonal changes, stress, and immuno-suppression seem to affect seborrheic dermatitis.[2]

Mechanism[edit]

Dandruff scale is a cluster of corneocytes, which have retained a large degree of cohesion with one another and detach as such from the surface of the stratum corneum. A corneocyte is a protein complex that is made of tiny threads of keratin in an organised matrix.[20] The size and abundance of scales are heterogeneous from one site to another and over time. Parakeratotic cells often make up part of dandruff. Their numbers are related to the severity of the clinical manifestations, which may also be influenced by seborrhea.[2]

Treatment[edit]

Nizoral (ketoconazole) 2% shampoo
Shampoos use a combination of special ingredients to control dandruff.

Antifungals[edit]

A number of antifungal treatments have been found to be effective including: ketoconazole, zinc pyrithione and selenium disulfide.[6] Ketoconazole as a shampoo appears to be the most effective.[6]
Ketoconazole is a broad spectrum, antimycotic agent that is active against both Candida and M. furfur. Of all the imidazoles, ketoconazole has become the leading contender among treatment options because of its effectiveness in treating seborrheic dermatitis as well.[2]
Ciclopirox is widely used as an anti-dandruff agent in most preparations.[21]

Coal tar[edit]

Coal tar causes the skin to shed dead cells from the top layer and slows skin cell growth.[22]

Alternative medicine[edit]

In traditional Indian[23] and Chinese medicine,[24] egg oil was used, but there is no evidence to indicate that it works.[citation needed]

Epidemiology[edit]

Dandruff affects up to half of adults.[6]

Etymology[edit]

According to the Oxford English Dictionary, the word dandruff is first attested in 1545, but is still of unknown etymology.[25]

References[edit]

  1. Jump up ^ Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. ISBN 1-4160-2999-0. 
  2. ^ Jump up to: a b c d e f Ranganathan S, Mukhopadhyay T (2010). "DANDRUFF: THE MOST COMMERCIALLY EXPLOITED SKIN DISEASE". Indian J Dermatol. 55 (2): 130–134. doi:10.4103/0019-5154.62734. PMC 2887514free to read. PMID 20606879. 
  3. Jump up ^ "Mayo Clinic, Dandruff". Mayo Clinic, Dandruff. Mayo clinic. Retrieved 8 January 2016. 
  4. Jump up ^ Turkington, Carol; Dover, Jeffrey S. (2007). The Encyclopedia of Skin and Skin Disorders (Third ed.). Facts On File, Inc. p. 100. ISBN 0-8160-6403-2. 
  5. Jump up ^ "A Practical Guide to Scalp Disorders". Journal of Investigative Dermatology Symposium Proceedings. December 2007. Retrieved 2009-02-06. 
  6. ^ Jump up to: a b c d Turner, GA; Hoptroff, M; Harding, CR (Aug 2012). "Stratum corneum dysfunction in dandruff.". International Journal of Cosmetic Science. 34 (4): 298–306. doi:10.1111/j.1468-2494.2012.00723.x. PMC 3494381free to read. PMID 22515370. 
  7. Jump up ^ "What Is Dandruff? Learn All About Dandruff". Medical News Today. 
  8. ^ Jump up to: a b http://www.mayoclinic.com/health/dandruff/DS00456/DSECTION=causes
  9. Jump up ^ DeAngelis YM, Gemmer CM, Kaczvinsky JR, Kenneally DC, Schwartz JR, Dawson TL (2005). "Three etiologic facets of dandruff and seborrheic dermatitis: Malassezia fungi, sebaceous lipids, and individual sensitivity". J. Investig. Dermatol. Symp. Proc. 10 (3): 295–7. doi:10.1111/j.1087-0024.2005.10119.x. PMID 16382685. 
  10. ^ Jump up to: a b Ro BI, Dawson TL (2005). "The role of sebaceous gland activity and scalp microfloral metabolism in the etiology of seborrheic dermatitis and dandruff". J. Investig. Dermatol. Symp. Proc. 10 (3): 194–7. doi:10.1111/j.1087-0024.2005.10104.x. PMID 16382662. 
  11. Jump up ^ Ashbee HR, Evans EG (2002). "Immunology of Diseases Associated with Malassezia Species". Clin. Microbiol. Rev. 15 (1): 21–57. doi:10.1128/CMR.15.1.21-57.2002. PMC 118058free to read. PMID 11781265. 
  12. Jump up ^ Batra R, Boekhout T, Guého E, Cabañes FJ, Dawson TL, Gupta AK (2005). "Malassezia Baillon, emerging clinical yeasts". FEMS Yeast Res. 5 (12): 1101–13. doi:10.1016/j.femsyr.2005.05.006. PMID 16084129. 
  13. ^ Jump up to: a b Dawson TL (2006). "Malassezia and seborrheic dermatitis: etiology and treatment". Journal of cosmetic science. 57 (2): 181–2. PMID 16758556. 
  14. Jump up ^ Gemmer CM, DeAngelis YM, Theelen B, Boekhout T, Dawson Jr TL (2002). "Fast, Noninvasive Method for Molecular Detection and Differentiation of Malassezia Yeast Species on Human Skin and Application of the Method to Dandruff Microbiology". J. Clin. Microbiol. 40 (9): 3350–7. doi:10.1128/JCM.40.9.3350-3357.2002. PMC 130704free to read. PMID 12202578. 
  15. Jump up ^ Gupta AK, Batra R, Bluhm R, Boekhout T, Dawson TL (2004). "Skin diseases associated with Malassezia species". J. Am. Acad. Dermatol. 51 (5): 785–98. doi:10.1016/j.jaad.2003.12.034. PMID 15523360. 
  16. Jump up ^ http://www.nature.com/articles/srep24877
  17. Jump up ^ "Genetic code of dandruff cracked". BBC News. 2007-11-06. Retrieved 2010-04-30. 
  18. Jump up ^ Pierard-Franchimont C, Hermanns JF, Degreef H, Pierard GE (2006). "Revisiting dandruff". Int J Cosmet Sci. 28 (5): 311–318. doi:10.1111/j.1467-2494.2006.00326.x. PMID 18489295. 
  19. Jump up ^ Pierard-Franchimont C, Hermanns JF, Degreef H, Pierard GE. From axioms to new insights into dandruff. Dermatology 2000;200:93-8.
  20. Jump up ^ http://dermatology.about.com/od/anatomy/ss/sc_anatomy_2.htm
  21. Jump up ^ Milani, M; Antonio Di Molfetta, S; Gramazio, R; Fiorella, C; Frisario, C; Fuzio, E; Marzocca, V; Zurilli, M; Di Turi, G; Felice, G (2003). "Efficacy of betamethasone valerate 0.1% thermophobic foam in seborrhoeic dermatitis of the scalp: An open-label, multicentre, prospective trial on 180 patients". Current Medical Research and Opinion. 19 (4): 342–5. doi:10.1185/030079903125001875. PMID 12841928. 
  22. Jump up ^ WebMD: Anti-Dandruff (coal tar)
  23. Jump up ^ H. Panda (2004). Handbook On Ayurvedic Medicines With Formulae, Processes And Their Uses. ISBN 9788186623633. 
  24. Jump up ^ Zhong Ying Zhou; Hui De Jin (1997). Clinical manual of Chinese herbal medicine and acupuncture. ISBN 9780443051289. 
  25. Jump up ^ "dandruff | dandriff, n." OED Online. Oxford University Press, March 2015. Web. Retrieved 27 April 2015.
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