acne

from Wikipedia, the free encyclopedia
Classification according to ICD-10
L70 acne
ICD-10 online (WHO version 2019)

Acne (possibly from ancient Greek ἀκμή AKME "tip, sharpness, zenith, acme "), formerly Finn rash called, is a collective term for diseases of the sebaceous glands apparatus and the hair follicles , the first non-inflammatory blackheads ( comedones produce), in the later stages but also a number of inflammatory Efflorescences such as papules , pustules and lumps can arise. The sebum follicles are mostly affected , in some forms of acne the terminal and vellus hair follicles .

The most common areas of the body affected are the face, the upper part of the chest and back, and the neck area.

Skin symptoms or diseases that are similar to acne are also called acneiform (from Latin acneiformis ).

etymology

This article or section needs to be revised: Several ambiguities or deficiencies in the section Etymology:

  • "There they referred to a late Latin source" - please, more precisely, to whom or what was they referring to? In addition: with the citation of "Aëtios of Amida wrote Aknas around 542" it is possibly a Middle Latin and not a Late Latin source. However, according to www.dictionary.com/browse/acne?s=t, the English word comes from Neo-Latin. That's a huge difference.
  • "Aëtios von Amida wrote at 542 Aknas " - please, more precisely: where did he write this (work title, section - source can be inserted via ref) and what exactly did he write? It would be obvious that he wrote something like the Greek ἀκνάς aknás (possibly as a prescription of ἀκμάς and as an accus. Pl. Of a fictional nom. Sg. * Ἀκνή * aknḗ ).
  • "Acnae or acne was" - what does that or mean? Are there both terms (e.g. as a singular word acne and as a plural word acnae )? Is one name a Middle Latin spelling of the other? Is one form an inflected form of the other (e.g. acne with gen. Acnae, 1st Decl.)? In addition: is it actually with a capitalized first letter?
  • "Greek accusative plural Akmas " - that is not Greek, but only a poor transcription. Alcohol and accent? Obvious is ἀκμάς akmás , Akk. Pl. From ἀκμή akmḗ .
    Please help to improve it , and then remove this flag.

The etymology of acne (as a term for the skin disease ) is not clearly understood. The word was borrowed from English into German in the 19th century . Reference was made to a late Latin source ( Aëtios von Amida wrote Aknas around 542 , from which Latin translated acnae , written in Middle Latin acne ), which in turn was possibly due to an error in the transmission from the Greek accusative plural akmás (plural of akmḗ : 'Höhe ', as a metaphor for' puberty ') made ac n as in Latin . According to Kluge , the introduction took place in English in the sense of "blossom" in originally English rosy-drop , according to the Online Etymology Dictionary , derived from the pointed appearance of the acne efflorescences papules and pustules . The Greek word ἀκμή aknḗ is related to the Greek ἄκρος ákros "(the) extreme, uppermost, highest" (compare in German medical usage the acra , also acrobat ) as well as originally related to the Latin acutus , "sharp, pointed; acute ”and German corner .

Epidemiology

Acne has been known since ancient times and is the most common skin disease worldwide. 70 to 95 percent of all adolescents have acne skin changes, particularly the face and upper trunk area . The incidence of the disease peaks between the ages of 15 and 18 years. In the majority of cases, spontaneous regression occurs after puberty , of which 2 to 7 percent result in significant scarring . In 10 percent of the cases, the disease persists beyond the age of 25. 10 to 30 percent of those affected require drug therapy.

Forms of acne

Acne is systematized according to age, cause and severity or severity.

Acne vulgaris in a 14 year old boy

The best known and most common is acne vulgaris or "common acne", sometimes also called acne simplex . “Ordinary” here means that the acne occurs due to the increased androgenic influence during puberty and subsides by the beginning of the third decade at the latest. Because its causes lie in changes in the body's metabolism, acne vulgaris is one of the endogenous forms of acne.

A distinction is also made according to age:

Endogenous acne is possible in principle at any age. Metabolic diseases come into consideration as background in particular in prepubertal and advanced adulthood .

But acne can also be caused "externally". Well-known exogenous forms of acne are:

Different forms of acne

The Acne inversa is a frequently severe inflammation of the sebaceous glands and terminal hair , preferably in intertriginous areas such. B. armpit, groin and gluteal folds. The pathogenesis is not fully understood; tobacco smoking often appears to play a role as a special exogenous factor .

A distinction is made between acne comedonica, acne papulo-pustulosa and acne conglobata, depending on the severity and severity. The complexion of acne comedonica is characterized by comedones and at most a few, very slight inflammations ( papules ). Scarring is not to be feared. When Acne papulopustulosa dominate papules and pustules , scarring as a result of inflammatory processes is possible. The acne conglobata designates the additional occurrence of Fistulated and nodes in the sequence threatens significant scarring.

Pathogenesis

Due to increased production of sebum ( seborrhoea ) and a keratinization in the output of the sebaceous follicle are formed comedones . If these become inflamed, papules, pustules or nodules develop. Acne is one of the diverse (polymorphic) skin diseases with a complex genetic background. Studies on homozygous twins showed that both twins were affected very similarly in 98 percent of the cases in terms of age of onset, sebum production rate and number of comedones. In contrast, a study with heterozygous twins found that only one twin was affected in half of the cases. Also in these cases there were little to no similarities in terms of sebum production and number of comedones. A familial accumulation was observed: If both parents had acne, then the risk of acne disease for their children is over 50 percent.

Other causes are:

  • Bacteria : Recent research results show that the onset of the acne inflammatory process does not require excessive colonization (hypercolonization) with Propionibacterium acnes . Nonetheless, the bacteria that occupy the resulting wound play a role in the further course of the inflammatory process.
  • Androgens : Androgens stimulate the increase in the volume of the sebum gland (sebum hyperplasia) as well as keratinocyte proliferation or the development of proliferation hyperkeratosis in the duct of the affected follicle.
  • Ligands of peroxisome - proliferation- activating receptors (PPAR): Human sebum glands are lavishly equipped with PPAR. Among the various PPAR subtypes, PPARα is particularly involved in the regulation of lipid synthesis. The 5-lipoxygenase product leukotriene B4 (LTB4) is one of the strongest naturally occurring PPARα ligands and, together with androgens, stimulates lipid synthesis in the sebum glands.
  • Comedogenic substances: Due to their material properties, comedogenic substances from cosmetics, for example, prevent the exfoliation of the corneocytes ( retention hyperkeratosis ) and thus promote the formation of comedones (comedogenesis).
  • Smoking : Research showed that cigarette smoke contains high amounts of arachidonic acid and polycyclic aromatic hydrocarbons. These initiate a phospholipase A2 -dependent signaling pathway that can further stimulate the pro-inflammatory effect of arachidonic acid.
  • Stress : The stress hormone CRH can influence the lipid genesis and the conversion of DHEA to testosterone in the sebocytes . To what extent this has an effect in practice and whether the knowledge opens up new therapeutic approaches remains to be clarified.

Consequences and complications

Acne-related inflammation can be accompanied by redness, swelling, itching, and tenderness . In the case of major inflammations, there is also the risk of swelling of the lymph nodes , headache, fever and sepsis . The outbreak of folliculitis / furunculosis can be promoted by smear infection . Heaviness, d. H. highly inflammatory forms of acne are associated with scarring . Furthermore, acne can lead to psychological and social problems for those affected, as it is perceived as stigmatizing . Phobic disorders , neuroses , relationship disorders , bullying of the person affected by their social environment, depression and suicidality are possible.

treatment

Except in mild acne cases, treatment by a dermatologist is recommended. There are several active ingredients and supportive therapy methods available. Drug therapy tries to reduce sebum production, normalize the cornification process in the duct of the sebum follicle , fight bacteria and favorably influence the inflammatory reaction.

Alpha Hydroxy Acids

α- Hydroxycarboxylic acids , which are among the natural " fruit acids ", have a comedolytic effect. In addition to glycolic acid , lactic acid , malic acid , citric acid and mandelic acid are used for acne therapy. With the help of 10–15% cream preparations, the cohesion of follicular corneocytes in the lower layers of the stratum corneum is reduced, and finally comedolysis. In most cases, however, a 3-month treatment is necessary for this. There is also a prophylaxis against new comedone formation . In contrast to therapy with benzoyl peroxide , retinoids or salicylic acid , there is no epidermal water loss when using alpha-hydroxy acids . The peeling with 30% glycolic acid, repeated every 2 weeks, proved to be significantly effective from the second treatment onwards.

Antibiotics

Antibiotics are supposed to fight the bacteria that colonize the sebum follicles and, later, the inflammatory efflorescences of acne. Antibiotics can also have anti-inflammatory effects and indirectly counteract the cornification disorder. A distinction is made between topically (locally) and systemically (body-wide) effective antibiotic preparations.

Benzoyl peroxide (short: BPO)

Tube of benzoyl peroxide gel

Benzoyl peroxide has an antibacterial and keratolytic effect as a potent oxidizing agent . There are BPO preparations in proportions of 2.5% to 10%, as a gel, cream or washing suspension. A higher proportion of BPO does not necessarily have to mean a better effect, but in some cases increases the skin irritation. Contact allergic reactions occur in about 10% of all cases and the drug should then be discontinued.

Hormones (women only)

The hormonal therapy of women involves the administration of antiandrogen active substances; they influence sebum production and cornification processes in the sebum follicle. For this purpose, the synthetic estrogen ethinylestradiol , combined with an antiandrogenic synthetic gestagen ( e.g. cyproterone acetate , drospirenone), is usually taken. Appropriate hormone preparations also serve as contraception .

Linoleic acid

Linoleic acid cream is used as the basis of magistral recipes . A study from 1998 showed that topical linoleic acid reduced the size of microcomedones by almost 25% within one month.

Retinoids

In the case of mild and moderate acne, the external (topical) application of retinoids is recommended . These include tretinoin , isotretinoin , motretinide , adapalene and tazarotene . Retinoids are primarily comedolytic when applied topically. Itching, burning and reddening of the skin can occur as side effects. Adapalen, a synthetic derivative of naphthoic acid , assigned to the “third generation retinoids” (polyaromatic retinoids), shows good results in low concentrations (0.1%) with comparatively few side effects.

Isotretinoin systemic

In severe or otherwise therapy-resistant cases of acne, the retinoid isotretinoin can be used systemically. Ideally, this will permanently reduce sebum production. The side effects can include severe peeling of the skin, dry skin, hair loss, nosebleeds, depression and joint pain, and damage to the liver (depending on the prescribed dose). Pregnancy must be ruled out for the duration of the therapy and with a subsequent safety margin, as severe malformations could occur in the unborn child. To ensure contraception , women on systemic isotretinoin therapy are usually prescribed the pill .

light therapy

Therapy with sunlight or ultraviolet radiation is controversial. Although UV radiation can have an antibacterial effect, it can also stimulate proliferation hyperkeratosis . As a result, there is a risk of new comedones . In addition, phototoxic effects can occur, especially when using externally applied drugs, sunscreens and cosmetics. The IGeL monitor of the MDS ( Medical Service of the Central Association of Health Insurance Funds ) examined the study situation on light therapy for acne with blue and red light in 2018. Although there were occasional slight advantages of light therapy, the IGeL monitor rated this self-payer service as “unclear” due to the methodological weaknesses of the studies. There is neither sufficient evidence of benefit nor harm. The evaluated studies showed certain positive effects of the light therapy, but these advantages are small, inconsistent and poorly proven. The most important source for the evaluation of the IGeL-Monitor are two reviews from 2016 and 2008. The guideline of the German Dermatological Society also evaluates the light therapy cautiously. In the case of mild to moderate papulopustolous acne, “therapy with blue light in combination with topical and systemic therapies can be considered,” it says, but “a direct effect on comedones [blackheads] is not to be expected. Severe acne courses do not improve. "

Salicylic acid

The aromatic β - hydroxycarboxylic acid salicylic acid has a keratolytic and antibacterial effect . Salicylic acid is contained in cosmetics in concentrations of up to two percent, but only has a superficial “peeling effect”. Only concentrations of five percent or more achieve a comedolytic effect. When used over a large area in higher doses, such as for the treatment of acne scars, there is a risk of kidney damage. The peeling with 30% salicylic acid (dissolved in water), repeated every 2 weeks, proved to be significantly effective from the second treatment onwards.

Zinc compounds

Zinc is an essential trace element for the human body. The pathomechanism of acne and wound healing processes can increase the patient's physiological needs. If this additional requirement cannot be met from food alone, it makes sense to use zinc supplements to support acne therapy. Chronic overdose should be avoided, however, as there is a risk of copper deficiency and, as a result, hypochromic anemia . For topical acne therapy, zinc compounds are usually combined with the antibiotics erythromycin and clindamycin . The antiseptically effective zinc oxide is part of the zinc ointment , which can be used alone or in combination with an antibiotic for wound treatment.

Auto vaccine

Vaccination with homologous car vaccines is an old, little-known form of therapy in western Europe for inflammatory acne lesions. To do this, a puncture must be taken from an infected lesion and sent to a laboratory. It takes about three weeks to produce the auto vacancy. The preparation is then injected subcutaneously once a week over a period of eight to ten weeks . Clinical trials have so far only provided indications of possible immunological effects. Evidence of safety and efficacy in acne has not yet been provided, a corresponding placebo-controlled double-blind study is still missing.

Scar treatment

Injections with cortisone or collagen can be used for acne scars . Fillings based on acrylic particles can lead to the formation of granulomas and sometimes disfiguring complications, sometimes only many years after the injection. Fractional lasers and radio frequency , microneedling and chemical peels are an alternative . They appear to be superior to non-fractionated, non-ablative lasers in terms of their effectiveness. However, the evidence from the studies that are available on the treatment of acne scars is not yet sufficient to make clear recommendations.

Acne and diet

Until now, there has been no scientific evidence of a general link between diet and the occurrence of acne.

Certain metabolic diseases are known which occur due to malnutrition and which can either cause acne or at least have an unfavorable effect. These include malnutrition-related cases of polycystic ovary syndrome , the hyperandrogenism of which leads to acne. Pathologically elevated blood sugar , as occurs in cases of untreated diabetes mellitus , can promote bacterial colonization of the skin and subsequent inflammation, which is likely to have an adverse effect on the severity of existing acne.

A retrospective, statistical, non-placebo-controlled study by Clement Adebamowo (Boston / USA) from 2005 claims that, by evaluating the questionnaires of over 47,000 nurses, a statistical connection was found between the consumption of certain dairy products and the occurrence of acne in young women to have.

In 2007, a research group from the University of Melbourne examined the influence of the glycemic load on the hormonal balance and the course or healing of acne vulgaris in 43 male test subjects over twelve weeks. After this period, the number of lesions in the group with low glycemic load decreased by around eight percent more than in the control group. In 2012, Kwon et al. in a comparative study with a total of 32 participants with mild to moderate acne, that reducing the glycemic load for a period of 10 weeks resulted in "significant improvements" in the number of non-inflammatory and inflammatory acne lesions. Histopathology showed, among other things, a reduced size of the sebum gland and a reduced inflammation. In 2015, authors of the Cochrane Collaboration rated the quality of the evidence in the studies on the topic as too “low” to be able to draw conclusions about the reliability of the outcome of this therapeutic intervention.

Errors and prejudices

  • "Acne is a sign of poor
    personal hygiene     ." Acne cannot be viewed as a lack of personal hygiene, so constant washing does not usually improve the complexion. On the contrary - too frequent washing damages the protective acid mantle of the skin, which could worsen the disease. Therefore, those affected should only wash a maximum of twice a day with a pH skin-neutral (pH 5.5) skin cleanser.
  • “ Sexual thoughts and actions lead to acne.”
    Admittedly, pubertal acne often manifests itself at the same time as the awakening of sexuality, but understanding the skin disease as a result of sexual thoughts and actions is a gross misunderstanding of endocrinological backgrounds.
  • "You should
    squeeze out     blackheads and pimples." "Squeezing out" acne efflorescences is not a sensible alternative to drug therapy, it should only be done in exceptional cases and by trained personnel. If the procedure is not carried out properly, there is a risk of rupture of the follicle or enlargement of the wound , abscess formation , smear infections and additional scars .
  • "Acne is caused by food that the body cannot digest."
    Acne is neither a symptom of an allergy nor a symptom of a food intolerance .
  • "Acne is hereditary."
    The acne vulgaris is a multifactorial disease with genetic predisposition . This means that can be Inherited predisposing factors for the disease such as seborrhea and the condition of the sebaceous glands , not the acne itself It is of one. Polygenic , autosomal - dominant inheritance with different penetrance of.

See also

literature

  • Treatment of acne - guidelines of the German Dermatological Society (DDG) , status: 10/2011. awmf.org (PDF)
  • Fanta, Messeritsch-Fanta, Steyr: Acne 1999: do we still need a dermatologist? . In: The dermatologist , 12/1999; Pp. 900-911; doi : 10.1007 / s001050051009 (pathogenesis and therapy of acne based on knowledge from 1999)
  • Zouboulis: Modern Aspects of Acne Pathogenesis . In: Akt Dermatol 2006; 32: 296-302; Georg Thieme Publishing House. doi: 10.1055 / s-2006-944576 .
  • HP Gollnick, CC Zouboulis: Not all acne is acne vulgaris. In: Dtsch Arztebl Int , 2014, 111, pp. 301–312, doi: 10.3238 / arztebl.2014.0301 , full text (PDF; German).
  • P. Schweikert-Wehner: Acne through medication, Der Hausarzt 10/2020, pp. 2-4, mmmedizin + Medien Verlag, Munich 2020

Web links

Commons : Acne  - Collection of Pictures, Videos and Audio Files
Wiktionary: Acne  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ Fin rash . In: Lexicon of Biology . Spectrum Academic Publishing House, Heidelberg 1999.
  2. ↑ a b acne . In: Roche Lexicon Medicine . 5th edition. Urban & Fischer, 2003. elsevierhealth.com ( Memento from September 20, 2017 in the Internet Archive ).
  3. ↑ Marina Bährle-Rapp: akneiform In: Springer Lexicon Cosmetics and Body Care , p. 16, 3rd edition, Springer 2007. ISBN 3-540-71094-9 ( limited preview in the Google book search).
  4. ↑ a b c Kluge: Etymological dictionary of the German language , 24th edition
  5. ↑ Thomas Jansen: Acne. In: Werner E. Gerabek , Bernhard D. Haage, Gundolf Keil , Wolfgang Wegner (eds.): Enzyklopädie Medizingeschichte. De Gruyter, Berlin / New York 2005, ISBN 3-11-015714-4 , pp. 24-26; here: p. 24.
  6. ↑ a b Harper: acme and acne In: Online Etymology Dictionary (English) website .
  7. Jump up ↑ Ghodsi SZ, Orawa H, Zouboulis CC .: Prevalence, severity, and severity risk factors of acne in high school pupils: A community-based study. In: Journal of Investigative Dermatology . 2009; 129: 2136-2141. PMID 19282841 full text .
  8. ↑ CC Zouboulis: Modern acne therapy In: Akt Dermatol 2003; 29: 49-57 full text (PDF; 116 kB).
  9. ^ Breuninger and Wienert: Acne inversa . In: Deutsches Ärzteblatt 2001 ; 98: A 2889-A2892 (issue 44). Full text .
  10. ^ William J Cunliffe, Harald PM Gollnick: 5th Clinical Aspects of Acne In: Acne: Diagnosis and Therapy , 1st Edition, Martin Dunitz - Taylor & Francis Group 2004; Pp. 64-65. ISBN 1-84184-404-7 .
  11. ↑ C. Borelli, G. Plewig, K. Degitz: Pathophysiology of Acne In: The dermatologist , Volume 56, Number 11 (2005); Pp. 1013-1017. doi: 10.1007 / s00105-005-1043-1 . Full text  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. .@1@ 2Template: Dead Link / resources.metapress.com  
  12. ↑ Zouboulis et al .: CRH: An autocrine hormone that promotes lipogenesis in human sebocytes . In: Proc Natl Acad Sci USA ; May 14, 2002; 99 (10): 7148-7153. Full text .
  13. ↑ Gieler et al .: Psychosomatic aspects of skin diseases: Acne vulgaris In: Psychosomatic Dermatologie ; AWMF Guideline Register No. 013/024. AWMF website .
  14. ↑ A. Fratila, M. Uerlich: Fruchtsäurepeeling - The dermatological and aesthetic-corrective application of alpha-hydroxy acids (AHA) In: Der Hautarzt 1999, 50: 457; doi : 10.1007 / s001050050942 .
  15. ^ A b E. Kessler, K. Flanagan, C. Chia, C. Rogers, DA Glase: Comparison of alpha- and beta-hydroxy acid chemical peels in the treatment of mild to moderately severe facial acne vulgaris. In: Dermatologic Surgery . 2008 Jan; 34 (1): 45-50; PMID 18053051 .
  16. ↑ Bodokh, Jacomet, Lacour, Ortonne: Minocycline induces an increase in the number of excreting pilosebaceous follicles in acne vulgaris. A randomized study. In: Acta Dermato-Venereologica . 1997 Jul; 77 (4): 255-9. PMID 9228213 .
  17. ↑ C. Letawe, M. Boone and GE Pierard: Digital image analysis of the effect of topically applied linoleic acid on acne microcomedones . In: Clinical and Experimental Dermatology , 1998 Mar; 23 (2): 56-58. PMID 9692305 .
  18. ^ IGeL monitor: light therapy for acne . accessed on February 14, 2019. More on the justification for the assessment in evidence in detail . (PDF) accessed on February 14, 2019.
  19. ↑ IGel-Monitor sees neither benefit nor harm from light therapy for acne . In: Deutsches Ärzteblatt , February 21, 2018.
  20. ↑ M. Haedersdal et al .: Evidence-based review of lasers, light sources and photodynamic therapy in the treatment of acne vulgaris ]. In: J Eur Acad Dermatol Venereol , 2008 Mar; 22 (3), pp 267-278, PMID 18221341 . and Barbaric, J. et al. Light therapies for acne . Cochrane Database Syst Rev. 2016 Sep 27; 9: CD007917
  21. ↑ Guideline treatment of acne . (PDF) 2010, in revision.
  22. ^ AA Hartmann: The influence of various factors on the human resident skin flora. In: Seminars in Dermatology . 1990 Dec; 9 (4): 305-8. PMID 2285575 .
  23. ↑ E. Zaluga: Skin reactions to antigens of Propionibacterium acnes in patients with acne vulgaris Treated with auto vaccine In: Ann Acad Med Stetin , 1998; 44: 65-85 PMID 9857532
  24. ↑ O. Nolte: How does an autogenous vaccine work? In: Therapeutic autogenic vaccination ("autovaccine") to influence bacterial infectious diseases. website
  25. ↑ Ogilvie, Patricia: Collagen-based fillers for acne scars. In: Aesthetic dermatology & cosmetology , Springer Medicine 2014, No. 3, pp. 16-17. skin-concept.de (PDF) accessed on May 30, 2015.
  26. ↑ Hay R. Abdel, K. Shalaby, H. Zaher et al .: Interventions for acne scars. In: Cochrane Database of Systematic Reviews 2016; Edition 4, article no. CD011946. PMID 27038134 . doi: 10.1002 / 14651858.CD011946.pub2 . Summary (German) .
  27. ↑ a b Herrmann Schell: Acne and nutrition In: Acne: the way to correct treatment , 2nd edition, p. 59; TRIAS - Thieme Hippokrates Enke, Stuttgart, 1992. ISBN 3-89373-184-9 .
  28. ↑ Adebamowo et al .: High school dietary dairy intake and teenage acne. In: Journal of the American Academy of Dermatology 02-2005; Pp. 207-214. Full text (PDF; 143 kB).
  29. ^ RN Smith, NJ Mann, A. Braue, H. Mäkeläinen, GA Varigos: The effect of a high-protein, low glycemic-load diet versus a conventional, high glycemic-load diet on biochemical parameters associated with acne vulgaris: a randomized , investigator-masked, controlled trial. In: Journal of the American Academy of Dermatology . 2007 Aug; 57 (2): 247-256 PMID 17448569 .
  30. ↑ HH Kwon, JY Yoon, JS HONg, J. Jung, MS Park, DH Suh :: Clinical and histological effect of a low glycaemic load diet in treatment of acne vulgaris in Korean patients: a randomized, controlled trial. In: Acta dermato-venereologica , 92 (3), 2012, pp. 241-246.
  31. Jump up ↑ Cao H, Yang G, Wang Y, Liu JP, Smith CA, Luo H, Liu Y .: Complementary therapies for acne vulgaris. In: Cochrane Database Syst Rev. 2015 Jan 19; 1: CD009436. doi: 10.1002 / 14651858.CD009436.pub2 . PMC 4486007 (free full text).
  32. ↑ P. Girbig, U. Siemann-Harms; Ingrid Moll (Ed.): 16.1 Acne vulgaris In: Duale Reihe - Dermatologie , 6th edition, Georg Thieme Verlag, Stuttgart 2005; P. 472. ISBN 3-13-126686-4 .