Acne Vulgaris

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 (P. acnes) causing an inflammatory reaction.

Comedones (follicles impacted and distended by incompletely desquamated keratinocytes and sebum) may be closed (blackheads) or open (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.
• 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 pre-menstrual.
• 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 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.
• Acne lesions may extend beyond the face to the shoulders, back and chest.
• 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, e.g. virilising tumour.

Severe acne is a serious disease in that it is disfiguring and has enormous psychological impact, and requires referral to a dermatologist.

Non-drug

• 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.
• Sunlight or artificial ultraviolet light can be beneficial, especially for those lesions off the face. The usual warnings about sun exposure should be given.
• Although there has been some evidence of the importance of diet,² a systematic review was unconvinced about the value of diet, hygiene, face washing and sunlight.³
• 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 is used for a variety of cosmetic procedures, including the improvement of photoageing, hyperpigmentation, acne, scars and stretch marks.
  • Despite its widespread use, little is known about its mechanism of action but it does seem to be simple, safe and effective.⁴
• There is interest in laser treatment and phototherapy as treatment for acne.^5,6 They tend to be reserved for more severe cases.⁷
• Many men who suffer significant acne into adult life choose to grow a beard to hide it.

Drugs

Topical preparations

• 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 cyproterone in an alcoholic lotion is effective but is still used only for girls.⁸
• 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.

Systemic treatments

• 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.
• Antibiotics:
  • Oxytetracycline is first line but erythromycin or clindamycin may also be used. The tetracyclines have anti-inflammatory as well as antibiotic effects.⁹
  • Minocycline is no more effective than oxytetracycline but it is significantly more expensive. Minocycline may cause autoimmune hepatitis and an SLE-like syndrome and so liver function tests and autoantibodies should be checked 3 months after starting minocycline.
  • 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.¹⁰
• Anti-androgen treatment:
  • A predominantly oestrogenic oral contraceptive is an effective treatment for acne.¹¹
  • Contraceptive pills containing norethisterone should be avoided because of its androgenic properties.¹²
  • A combination of 50 μg of ethinylestradiol with the anti-androgen cyproterone is available as Dianette®. It is an effective contraceptive but is not licenced as a contraceptive and the patient must be told.
  • Dianette® is the most effective hormonal intervention.¹³ 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.
  • 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 istotretinoin and psychiatric adverse events.¹⁴
• Treatment for scarring:
  • Laser resurfacing, dermabrasion and chemical peels are used in the treatment of acne scarring.
  • Punch excision or collagen injections can be used for pitted scars.
  • Unfortunately treatment for acne scarring is often disappointing.

Referral

NICE recommends that:¹⁵

• People who have a severe variant of acne including acne fulminans or Gram-negative folliculitis should be referred urgently to be seen within 2 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.¹⁶
• 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.¹⁷
• Infantile acne usually disappears within one or two years but may persist to puberty.

• Acne causes a significant psychological and social morbidity, with anxiety, depression and a reduction in social functioning, which can be severe.¹⁸
• Any form of acne cam 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.¹
• Post-inflammatory hyperpigmentation may occur, especially in people with darker skin.¹
• 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 by age 20 but some continue into adulthood.