oPatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
Acne vulgaris is a disorder of the pilosebaceous follicles found in the face and upper trunk. At puberty androgens increase the production of sebum from enlarged sebaceous glands that become blocked and infected with Propionibacterium acnes causing an inflammatory reaction.
Comedones (follicles impacted and distended by incompletely desquamated keratinocytes and sebum) may be open (blackheads) or closed (whiteheads). Inflammation leads to papules, pustules and nodules.
Acne can cause severe psychological problems, undermining self-assurance and self-esteem at a vulnerable time in life.
- Almost every teenager can expect to experience acne to some degree during the adolescent years.
- Genetic factors play a part and a positive family history is often a factor; concordance among twins has been demonstrated.
- Acne tends to affect boys more than girls.
- Acne tends to occur in adolescence, when hormones are in a state of flux.
- In girls it may flare up when they are premenstrual.
- Acne may be associated with polycystic ovarian syndrome.
- Acne may result from abnormal production of androgens. This may occur in testosterone replacement therapy, abuse of anabolic steroids, Cushing's disease or in virilising tumours in women, such as arrhenoblastoma.
- Acne usually presents with a greasy skin with a mixture of comedones, papules and pustules, which present just after puberty and continue for a variable number of years, usually stopping in late teens or early 20s but uncommonly continuing well into adulthood.
- The face is affected in 99% of cases, the back in 60% and the chest in 15%.
- Acne runs a variable course with marked fluctuations.
- Nodulocystic acne: severe acne with cysts. Cysts can be painful. They may occur in isolation or be widespread over the face, neck, scalp, back, chest and shoulders.
- The severity of the condition varies enormously between individuals. It is unsightly but the degree of distress is sometimes disproportionate.
- Acne rosacea: usually presents in middle age or later in life.
- Folliculitis and boils: may present with pustular lesions similar to those seen in acne.
- Milia: small keratin cysts that may be confused with whiteheads. They tend to be whiter than acne whiteheads and are most commonly seen around the eyes.
- Perioral dermatitis.
- Pityrosporum folliculitis: predominates on the trunk.
- Usually no investigations are required.
- Investigations are occasionally required to explore a possible underlying cause, eg virilising tumour.
- Skin lesion culture may be warranted in patients who do not respond to treatment, to exclude gram-negative folliculitis.
Severe acne is a serious disease in that it is disfiguring, has enormous psychological impact and requires referral to a dermatologist.
- Usually acne is a mild and self-limiting condition but teenagers are very sensitive about it and so it is essential to be empathetic as well as providing advice and reassurance.
- Advise to keep the face clean, washing twice a day with soap and water but a more fastidious regimen may be counterproductive. Proprietary antiseptic products for acne may be beneficial.
- There is increasing evidence that diets with a high glycaemic load and those containing a large amount of dairy of milk products can aggravate acne. There is little evidence concerning the efficacy or lack of efficacy of face-washing or exposure to sunlight.
- Use of the 1450-nm laser promotes improvement in acne. Interestingly, this improvement is seen bilaterally in studies in which only one side of the face is treated, suggesting a systemic effect.
- Blue light phototherapy can be useful for mild-to-moderate papulopustular acne.
- Many men who suffer significant acne into adult life choose to grow a beard to hide it.
- Topical treatments need to be applied to all affected areas and not just to existing lesions. They are difficult to apply to the back and so widespread acne requires systemic treatment.
- Salicylic acid 10% is similar in action to retinoids.
- Azelaic acid is least irritating but it can cause hypopigmentation.
- For mild papulopustular acne, benzoyl peroxide reduces sebum production and comedones and inhibits the growth of P. acnes:
- It is mildly irritant and causes peeling after a few days.
- Start with 5% used sparingly; increase usage and/or concentration to 10% later.
- It tends to produce a burning sensation on the skin after application, especially if it is greasy.
- Benzoyl peroxide can be combined with topical clindamycin or erythromycin in gel preparations.
- Topical antibiotics:
- Topical erythromycin, clindamycin and tetracycline can be effective.
- Antibiotic resistance can be reduced and effectiveness increased by combining with zinc or benzoyl peroxide.
- Topical retinoids:
- Local treatment with isotretinoin, tretinoin or adapalene reduces comedones and has an anti-inflammatory effect.
- Avoid exposure to strong sunlight, which causes irritation that is greatest after a few weeks of treatment. The irritation can be treated with moisturisers. Adapalene is the least irritant.
- Systemic absorption is minimal but topical retinoids are still contra-indicated in pregnancy.
- Any systemic treatment often takes several months to show any improvement and should therefore be continued for 3-4 months, if tolerated, before effectiveness can be properly assessed.
- Systemic treatment may be combined with topical treatment.
- People with dark skin often need early systemic treatment because they can develop severe post-inflammatory pigmentation.
- Having reviewed the available literature, the European Dermatology Forum has concluded that no particular oral antibiotic demonstrates superiority with respect to efficacy, tolerability or safety.
- The most frequent adverse reactions for doxycycline are manageable (eg photosensitivity, oesophagitis), whereas those of minocycline are less so (eg hypersensitivity, hepatic like dysfunction, lupus-like syndrome). The safety profile of lymecycline is comparable to that of tetracycline. Doxycycline, lymecycline and minocycline are generally preferred to tetracycline because they require less frequent administration. Clindamycin is normally reserved for severe infections.
- Oral antibiotics have always been held to be more efficacious for mild-to-moderate papulopustular acne than topical antibiotics. However, the evidence base supporting this belief is equivocal. Topical benzoyl peroxide and benzoyl peroxide/erythromycin combinations are similar in efficacy to oral oxytetracycline and minocycline and are not affected by propionibacterial antibiotic resistance. Oral antibiotics are more appropriate if the lesions are widespread. They also demonstrate superiority in moderate-to-severe papulopustular acne.
- Anti-androgen treatment:
- A predominantly oestrogenic oral contraceptive is an effective treatment for acne.
- Contraceptive pills containing norethisterone should be avoided because of its androgenic properties.
- A combination of 50 micrograms of ethinylestradiol with the anti-androgen cyproterone is available as Dianette®. It is an effective contraceptive but is not licensed as a contraceptive and the patient must be told this.
- Dianette® is the most effective hormonal intervention. However, Yasmin® (ethinylestradiol with drospirenone) has also been found to be effective.
- Spironolactone has been shown to be effective for older women.
- Oral isotretinoin:
- The retinoid isotretinoin reduces sebum secretion.
- It is highly effective but toxicity problems confine its use to hospitals and under consultant supervision.
- Dry skin, lips and eyes are common. Raised serum lipids occur in a third of patients. Muscle aches and pains on strenuous exercise, hair thinning and acne flare-up also occur.
- The main problem is teratogenicity that continues to damage the fetus after discontinuation. Effective contraception is therefore essential in female patients, continued for one month after stopping treatment.
- Isotretinoin has had some causes for concern in that it has been associated with a variety of adverse psychiatric effects, including depression, psychosis, mood swings, violent behaviour, suicide and suicide attempts. However, a review of the evidence concluded that there is insufficient evidence to conclude a causal relationship between isotretinoin and psychiatric adverse events.
- Treatment for scarring:
- Laser resurfacing, dermabrasion and chemical peels are used in the treatment of acne scarring.
- Microdermabrasion is a simple outpatient procedure in which aluminum oxide crystals or other abrasive substances are blown on to the face and then vacuumed off, using a single handpiece. It has a limited role in the management of acne scars.
- Subcision is occasionally used to treat depressed acne scars. It involves inserting a tri-beveled hypodermic needle through a puncture in the skin surface and manoeuvering its edges to break down subcuticular fibrotic strands, thus releasing the skin from the underlying connective tissue. It appears to be equal in efficacy to collagen filler..
The National Institute for Health and Clinical Evidence (NICE) recommends that:
- People who have a severe variant of acne including acne fulminans or Gram-negative folliculitis should be referred urgently to be seen within two weeks.
- People who have severe acne such as painful, deep nodules or cysts (nodulocystic acne), or other people who could benefit from oral isotretinoin, should be referred as 'soon'.
- Milder cases with possible scarring or failure to get an adequate response require 'routine' referral.
- Acne - even severe acne - can occur in infants and neonates.
- Infantile acne is rare. It is more common in boys.
- It most often presents as comedones, papules and pustules on the cheeks at 3-6 months of age.
- Treatment for mild acne is topical antiseptics and antibiotics. Low-strength topical retinoids may be used to treat comedones.
- Severe acne requires systemic antibiotics (tetracyclines must be avoided).
- Severe cystic acne can be treated with oral isotretinoin.
- Infantile acne usually disappears within one or two years but may persist to puberty.
- Acne causes a significant psychological and social morbidity, with anxiety, severe depression and suicidal ideation. There can be a serious lack of self-esteem leading to social isolation. Bullying and stigmatisation can occur. Young people have been reported to have the same psychological difficulties as those suffering from more serious diseases such as asthma and diabetes.
- Any form of acne can lead to permanent scarring. Scarring usually results from deep lesions but superficial lesions can also cause scarring. Scarring is usually atrophic and hypertrophic or keloid scarring occurs less often.One person in five gets significant (ie socially obvious) scarring.
- Post-inflammatory hyperpigmentation may occur, especially in people with darker skin.
- Gram-negative folliculitis may occur as a complication of long-term oral erythromycin or tetracycline treatment. Treatment with trimethoprim may be effective.
Most cases clear up spontaneously before the age of 30 but some continue into adulthood.
Further reading & references
- Dawson AL, Dellavalle RP; Acne vulgaris. BMJ. 2013 May 8;346:f2634. doi: 10.1136/bmj.f2634.
- Acne Vulgaris, DermIS (Dermatology Information System)
- Simpson RC, Grindlay DJ, Williams HC; What's new in acne? An analysis of systematic reviews and clinically significant Clin Exp Dermatol. 2011 Dec;36(8):840-3; quiz 843-4. doi:
- Schnopp C, Mempel M; Acne vulgaris in children and adolescents. Minerva Pediatr. 2011 Aug;63(4):293-304.
- Guideline on the Treatment of Acne, European Dermatology Forum (September 2011)
- Fulton J, Acne Vulgaris, Medscape, Aug 2011
- Acne vulgaris; NICE CKS, June 2009
- Smith RN, Mann NJ, Braue A, et al; A low-glycemic-load diet improves symptoms in acne vulgaris patients: a Am J Clin Nutr. 2007 Jul;86(1):107-15.
- Magin P, Pond D, Smith W, et al; A systematic review of the evidence for 'myths and misconceptions' in acne management: diet, face-washing and sunlight.; Fam Pract. 2005 Feb;22(1):62-70. Epub 2005 Jan 11.
- Darne S, Hiscutt EL, Seukeran DC; Evaluation of the clinical efficacy of the 1,450 nm laser in acne vulgaris: a Br J Dermatol. 2011 Dec;165(6):1256-62. doi: 10.1111/j.1365-2133.2011.10614.x.
- Kim RH, Armstrong AW; Current state of acne treatment: highlighting lasers, photodynamic therapy, and Dermatol Online J. 2011 Mar 15;17(3):2.
- Karrer-Voegeli S, Rey F, Reymond MJ, et al; Androgen dependence of hirsutism, acne, and alopecia in women: retrospective Medicine (Baltimore). 2009 Jan;88(1):32-45.
- Purdy S, de Berker D; Acne. BMJ. 2006 Nov 4;333(7575):949-53.
- Tan J; Hormonal treatment of acne: review of current best evidence.; J Cutan Med Surg. 2004;8 Suppl 4:11-5.
- Joish VN, Boklage S, Lynen R, et al; Use of drospirenone/ethinyl estradiol (DRSP/EE) among women with acne reduces J Med Econ. 2011;14(6):681-9. Epub 2011 Sep 5.
- Kim GK, Del Rosso JQ; Oral Spironolactone in Post-teenage Female Patients with Acne Vulgaris: Practical J Clin Aesthet Dermatol. 2012 Mar;5(3):37-50.
- Layton A; The use of isotretinoin in acne. Dermatoendocrinol. 2009 May;1(3):162-9.
- British National Formulary
- Brito Mde F, Sant'Anna IP, Galindo JC, et al; Evaluation of clinical adverse effects and laboratory alterations in patients An Bras Dermatol. 2010 Jun;85(3):331-7.
- Karimipour DJ, Karimipour G, Orringer JS; Microdermabrasion: an evidence-based review. Plast Reconstr Surg. 2010 Jan;125(1):372-7.
- Chandrashekar B, Nandini A; Acne scar subcision. J Cutan Aesthet Surg. 2010 May;3(2):125-6.
- Sage RJ, Lopiccolo MC, Liu A, et al; Subcuticular incision versus naturally sourced porcine collagen filler for acne Dermatol Surg. 2011 Apr;37(4):426-31. doi: 10.1111/j.1524-4725.2011.01918.x. Epub
- Referral Advice. A guide to appropriate referral from general to specialist services; NICE Clinical Guideline (2001)
- Hello M, Prey S, Leaute-Labreze C, et al; Infantile acne: a retrospective study of 16 cases. Pediatr Dermatol. 2008 Jul-Aug;25(4):434-8.
- Infantile acne, DermNet NZ, 2012
- Misery L; Consequences of psychological distress in adolescents with acne. J Invest Dermatol. 2011 Feb;131(2):290-2.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Colin Tidy
Dr Laurence Knott
Dr Hannah Gronow