Acne

发布时间：2025-11-10 08:06

Acne — extra information

Categories:

Follicular disorder

ICD-10:

L70

ICD-11:

ED80.Z

SNOMED CT:

11381005

Follicular disorder

Author: Dr Amanda Oakley, Dermatologist, Hamilton, New Zealand, 2014. Previous contributor: Minor amendment by Ian Coulson, Dermatologist, 2024. Edited by the DermNet content department

Introduction Demographics Causes Clinical features Diagnostic tests Treatment Outlook

What is acne?

Acne is a common chronic disorder affecting the hair follicle and sebaceous gland, in which there is expansion and blockage of the follicle and inflammation. There are several variants.

Who gets acne?

Acne affects males and females of all races and ethnicities. It is prevalent in adolescents and young adults, with 85% of 16 to 18 year-olds affected. However, it may sometimes occur in children and adults of all ages.

What causes acne?

Acne is due to a combination of factors. The exact mechanisms are not fully understood.

Familial tendency Endogenous and exogenous androgenic hormones Acne bacteria Innate immune activation with inflammatory mediators Distension and occlusion of the hair follicles

Flares of acne can be provoked by:

Polycystic ovarian disease Drugs: steroids, hormones, anticonvulsants, epidermal growth factor receptor inhibitors and others Application of occlusive cosmetics High environmental humidity Diet high in dairy products and high glycaemic foods.

What are the clinical features of acne?

Acne is often confined to the face but it may involve the neck, chest, and back.

It is characterised by:

Open and closed uninflamed comedones (blackheads and whiteheads) Inflamed papules and pustules In severe acne, nodules and pseudocysts Post-inflammatory erythematous or pigmented macules and scars Adverse social and psychological effects.

Severity is classified as mild, moderate, or severe.

Mild acne: total lesion count <30 Moderate acne: total lesion count 30–125 Severe acne: total lesion count >125

What tests are necessary for acne?

In most cases, tests are unnecessary. If features are atypical consider:

Skin swabs for microscopy and culture Hormonal tests in females.

Comedonal acne

Acne vulgaris

Nodulocystic acne

See more images of acne:

Acne affecting the back images Facial acne images Steroid acne images.

What is the treatment for acne?

Mild acne

Topical anti-acne agents, such as benzoyl peroxide, azelaic acid, and tretinoin or adapalene gel and some antibiotics (clindamycin). New bioactive proteins may also prove successful. Newer topical agents such as clascoterone Low-dose combined oral contraceptive Antiseptic or keratolytic washes containing salicylic acid Light/laser therapy

Moderate acne

As for mild acne plus a tetracycline such as doxycycline 50–200 mg daily for 6 months or so Erythromycin or trimethoprim if doxycycline intolerant Antiandrogen therapy with long-term cyproterone acetate + ethinylestradiol or spironolactone may be considered in women not responding to low-dose combined oral contraceptive, particularly for women with polycystic ovaries Isotretinoin is often used if acne is persistent or treatment-resistant Intralesional steroid injections can be useful for acute larger acne lesions

Severe acne

Referral to a dermatologist If fever, arthralgia, bone pain, ulcerated or extensive skin lesions, blood count should be arranged and referral is urgent Oral antibiotics are often used in higher doses than normal Oral isotretinoin is usually recommended in suitable patients

What is the outlook for acne?

Acne tends to improve after the age of 25 years but may persist, especially in females.

Treatment with isotretinoin can lead to long-term remission in many patients.

Bibliography

Reynolds RV, Yeung H, Cheng CE, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol. 2024;90(5):1006.e1-1006.e30. PubMed

On DermNet

Acne pages Comedo Enlarged pores Facial acne images

Other websites

Acne, Rosacea, and Perioral Dermatitis — DermNet e-lecture [Youtube] Acne — Medline Plus Acne — emedicinehealth Clinical Guidelines — British Association of Dermatologists Acne: Patient Handouts — The Society for Pediatric Dermatology Patient information: A guide to acne — UpToDate for patients Acne — American Academy of Dermatology Systematic reviews on acne vulgaris — University of Nottingham

Books about skin diseases

Books about the skin Dermatology Made Easy - second edition