Acne: Clinic, diagnosis and treatment

Medical editor: Dr. Marina Alexandre, Dermatologist, Avicenne Hospital, France.

Written by

Dr. Marina Alexandre

Key messages:

Is a chronic inflammatory dermatosis of the pilosebaceous unit.
Often affects adolescents and young adults.
It can cause scars but also psychological consequences.
The diagnosis is clinical: there are two main types of lesions: retentional (microcysts and blackheads) and inflammatory (papules, pustules, and nodules).
Therapeutic strategy is different according to the type of lesion and its severity.
The efficacy of the treatments is not immediate, one must be patient.

Acne is a chronic dermatosis that develops during hormonal changes, particularly during adolescence. It is found in 90% of teenagers and over 40% of adults.
It affects the sebaceous glands, located at the base of the hair in the hair follicles.
A dysfunction of these follicles leads to an increased secretion of sebum which leads to a dysfunction of the synthesis of keratin.
This phenomenon leads to an obstruction of the skin pores and the appearance of acne specific lesions:
- Blackheads, also known as open comedones, or whiteheads, known as closed comedones or "microcysts".
- When bacterial proliferation occurs within closed comedones, they can become inflamed and generate non-purulent erythematous lesions (papules), purulent lesions (pustules) or larger, deeper lesions in the skin (nodules).

Good to know:

There is a potentially permanent risk of scarring.
Acne can have psychological consequences, such as mood disorders, depression, lowered self-esteem and relationship difficulties¹.

There are several determining factors in the development of acne:

Hyperseborrhea (increased sebum production by the sebaceous gland): a disturbance of the hormones responsible for the production of sebum (dihydrotestosterone and androgens) or an increased sensitivity of the receptors can be at the origin of the phenomenon of hyperseborrhea².
Hyperkeratinization of the follicular Infundibulum: comedones form as a result of an increase in the proliferation of keratinocytes in the pilosebaceous follicle coupled with abnormalities in their differentiation, which leads to an obstruction of the hair follicle canal².
Microbial flora and inflammation factors: in acne-prone skin, the anaerobic environment of the sebaceous follicles is dominated by Cutibacterium acnes (formerly known as Propionibacterium acnes³), a Gram-positive bacterium that is over-represented in the microbiome of acne-prone skin. This bacterium is responsible for the production of pro-inflammatory factors at the heart of acne physiopathogenesis².
Genetic factors: several studies suggest that there is a genetic background for acne. A history of acne in the first degree increases the risk of developing moderate to severe acne^4,5.

The different forms of acne are classified into three categories: common forms, severe forms and specific forms²:

The common forms

Juvenile Mixed Acne

Most common form of acne.
Appears at the time of puberty and may extend to the trunk.
Variable severity:
- Mild or moderate: superficial inflammatory and retentional lesions in varying numbers.
- If nodules are present: severe acne¹.

Retentional acne

Most common form of early acne.
Manifested mainly by microcysts and open comedones on the face.

The severe forms

Nodular acne or acne conglobate

Inflammatory nodules that may evolve into abscesses or fistulize deeply (sinuses).
Frequent extension to the trunk, especially in boys.
Chronic evolution with often significant scarring.

Acne fulminans (acute, febrile, ulcerative nodular acne)

Rare.
Sudden onset.
Develops more often in boys.
Associated with altered general condition with hyperthermia at 39-40°C, arthralgias, hyperleukocytosis and multiple inflammatory nodules that may become complicated with necrotic or hemorrhagic ulcerations.

The specific forms

Neonatal acne

Appears on the face in the first weeks following the infant's birth.
Regresses spontaneously within a few weeks.
Is due to maternal androgens.

Prepubertal acne

Early onset before puberty.
Mainly retentional.

Exogenous acne

Prevalence of retentional lesions (open comedones).
Related to prolonged contact with comedogenic substances, particularly certain mineral oils (massage oils, cosmetic acne, acne mechanica, milling cutters, garage workers, etc.).

Acne in adult women

Women over 25 years old.
Juvenile acne lasting into adulthood.
Rarely, late-onset acne in adulthood.
Characterized by the predominance of inflammatory papules or nodules located on the lower part of the face.

Acne excoriata

Almost exclusively found in women.
Lesions due to repeated manipulation of the facial skin, which is difficult to suppress, leading to erosions.
Sometimes an indicator of psychological difficulties.

There are 6 levels of acne severity^2,6.They are described according to a global severity assessment tool: Global Acne Evaluation (GEA)⁶.

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The different lesions found in acne have been classified as such^2,6:

Hyperseborrhea

Oily and shiny skin appearance.
Affects areas rich in sebaceous glands: central part of the face (nose, forehead, chin: T-zone, cheeks) and upper thoracic region (back and front of the chest).
Almost constant.

Retention lesions corresponding to distended pilosebaceous follicles

Two types: closed comedones and open comedones:

Closed comedones (or microcysts)

Small papules of 2 -3 mm, normal skin color, sometimes more palpable than visible.
Linked to the accumulation of sebum and keratin mixed in the follicular canal dilated by the obstruction of its orifice.
Possible secondary inflammation.

Open comedones (blackheads)

1-3 mm lesions following the accumulation of keratinocytes and oxidized sebum within the dilated orifice of the infundibular duct.
Possible secondary inflammation.

Inflammatory lesions

Superficial inflammatory lesions

Papules: lesions <10mm; often originating from a retention lesion; red, firm and sometimes painful.
Pustules: usually arise from papules at the top of which appears a yellow purulent content by accumulation of altered polynuclei.

Deep inflammatory lesions

Nodules: lesions <10 mm.
May evolve into abscesses and scars.
Rupture in the depth of the dermis giving sinuses, very painful elongated nodules.

Scars

4 types: atrophic, hypertrophic, erythematous, and pigmented.
Frequent.
Mostly secondary to inflammatory lesions.

The French Society of Dermatology has established an algorithm⁷ for the management of acne according to the patient's symptoms. It is described below:

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Do not squeeze/pierce blackheads.
Apply the topical treatment in the evening to the entire face, not just to the lesions. In the morning, apply a suitable moisturizer. It will improve the tolerance of topical treatments⁸.
"Skin cleansers" can only be a possible complement to treatment. To wash, use a mild, foaming, soap-free cleanser. The use of antiseptics, overly aggressive cleansers and mechanical exfoliation are not only useless but can be harmful⁹.
Make-up can be applied using "non-comedogenic" products and by carefully removing make-up and by cleansing the skin in the evening.
Although the sun temporarily reduces the inflammatory nature of lesions, it promotes comedogenesis by thickening the skin. The improvement often observed in the Summer is usually followed by a flare-up in the Autumn.
Photoprotection is essential when prescribing photo-sensitizing products, especially in the case of dark skin.
The role of diet in acne is still controversial; it is advisable to avoid ultra-processed foods, fast sugars and large quantities of dairy products^10,11.
The effects of the treatment are not immediate: it takes 3 to 4 weeks to start obtaining results and 3 to 4 months for them to be optimal. Patience and consistency are required.

What treatment can be offered to a pregnant woman?

Oral isotretinoin, topical retinoids and cyclins are strictly contraindicated. Topical antibiotic treatment may be used: benzoyl peroxide or azelaic acid. Oral zinc can be used from the second trimester onwards^1,12.

What to advise to the mother for the acne of the infant?

Reassure about the always temporary and spontaneously regressive nature of the flare-ups. Advise usual non-irritating hygiene care, no topical antiseptics. Possibly an erythromycin cream in 4% preparation in case of request for treatment.

What contraceptive methods are suitable for this condition?

As a first-line treatment, either a copper IUD or a second-generation estrogen-progestin is recommended. As a second-line treatment, norgestimate is recommended. If the acne persists after 3 months, consult a gynecologist.

What specific phenomenon explains infant acne?

Infant acne is due to persistent exposure to maternal hormones.

It seems to me that the copper IUD does not worsen acne and that estrogen-progestins improve it, is this true?

The copper IUD has no influence on acne, while estrogen-progestogens have a positive or negative influence, depending on whether they are anti or pro-androgenic.

How does the hormonal IUD affect acne?

In 10 to 15% of cases, it can cause or worsen acne^13,14.

What is the difference between papules, pustules, comedones and microcysts?

A papule is an erythematous lesion that is slightly infiltrated. A pustule has a white tip (cellular debris or pus). A comedo is an open cyst, whereas a microcyst has no opening to the skin.

What is Propionibacterium?

Propionibacterium acnes is the former name of Cutibacterium acnes. It is a bacterium that contributes to the pathophysiology of acne.

Acné : quand et comment la traiter ? [Internet]. Haute Autorité de Santé. [website consulted on 08/02/2023].https://www.has-sante.fr/jcms/c_2574402/fr/acne-quand-et-comment-la-traiter
CEDEF Collège des Enseignants en Dermatologie de France. Dermatologie. 8ème édition. Elsevier Masson; 2022. 471 p. (Les référentiels des Collèges).
Dictionnaire médical de l’Académie de Médecine [Internet]. [website consulted on 09/02/2023]. https://www.academie-medecine.fr/le-dictionnaire/index.php?q=%3Cem%3ECutibacterium+acnes%3C%2Fem%3E
Ballanger F, Baudry P, N’Guyen JM, Khammari A, Dréno B. Heredity: a prognostic factor for acne. Dermatol Basel Switz. 2006;212(2):1459.
Société française de dermatologie. Recommandations de bonne pratique : Traitement de l’acné par voie locale et générale. 10 juin 2015;113.
Dermatologie SF de. Évaluation de l’acné [Internet]. 2020 [website consulted on 07/02/2023]. https://reco.sfdermato.org/fr/recommandations-acn%C3%A9/%C3%A9valuation
Société française de dermatologie. algorithme-acné.pdf [Internet]. [website consulted on 07/02/2023]. https://document.sfdermato.org/groupe/centre-de-preuves/algorithme-acn%C3%A9.pdf?ss360SearchTerm=acn%C3%A9
Levin J. The Relationship of Proper Skin Cleansing to Pathophysiology, Clinical Benefits, and the Concomitant Use of Prescription Topical Therapies in Patients with Acne Vulgaris. Dermatol Clin. avr 2016;34(2):13345.
National Guideline Alliance (UK). Skin care advice for people with acne vulgaris: Acne vulgaris: management: Evidence review B [Internet]. London: National Institute for Health and Care Excellence (NICE); 2021 [website consulted on 10/02/2023]. http://www.ncbi.nlm.nih.gov/books/NBK573057/
Penso L, Touvier M, Deschasaux M, Szabo de edelenyi F, Hercberg S, Ezzedine K, et al. Association Between Adult Acne and Dietary Behaviors. JAMA Dermatol. août 2020;156(8):19.
doi:10.12788/cutis.0565 C 2022 J 16 |. What’s Diet Got to Do With It? Basic and Clinical Science Behind Diet and Acne [Internet]. [website consulted on 10/02/2023]. https://www.mdedge.com/dermatology/article/256058/acne/whats-diet-got-do-it-basic-and-clinical-science-behind-diet-and-acne/page/0/1
CRAT - Centre de référence sur les agents tératogènes chez la femme enceinte [Internet]. [website consulted on 08/02/2023]. https://www.lecrat.fr/
Notice patient - MIRENA 52 mg (20 microgrammes/24 heures), dispositif intra-utérin - Base de données publique des médicaments [Internet]. [website consulted on 09/02/2023]. https://base-donnees-publique.medicaments.gouv.fr/affichageDoc.php?specid=66349230&typedoc=N
HAS, Haute Autorité de Santé. CT-18944_DONASERT_PIS_INS_AvisDef_CT18944.pdf [Internet]. [website consulted on 09/02/2023]. https://www.has-sante.fr/upload/docs/evamed/CT-18944_DONASERT_PIS_INS_AvisDef_CT18944.pdf

Acne: Clinic, diagnosis and treatment

Digest

Key messages:

Definition

Etiology and physiopathology

Clinic

Diagnosis

Treatments

Advice for your patients

Questions your patients may have

References