Acne vulgaris

Prevalence

• 50% of adolescents will have acne.
• 10% will have severe acne.
• 10-20% of cases persist into adulthood.

Definition

• Chronic inflammatory disease of the pilosebaceous unit.

Common Demographics

• Adolescents and young adults.
• Males tend to resolve in early twenties.
• Females can persist into 30s/40s.

Pathogenesis

• Abnormal sebum production (due to androgens).
• Abnormal skin cell development and desquamation.
• Infection by Propionibacterium acnes (P. acnes).
• Inflammation.

Causes

• Familial/genetic tendency.
• Androgenic hormones and hormonal changes during puberty.
• Acne bacteria (P. acnes).
• Occlusive/comedogenic products.
• Polycystic Ovary Syndrome (PCOS).
• Drugs (e.g., steroids, hormones, anticonvulsants).
• High environmental humidity.
• Possible dietary factors (dairy/high GI foods).

Aggravating Factors

• Drugs.
• Topical products.
• Hormonal changes.
• Consider PCOS if hirsutism, obesity, or menstrual irregularity present.

Differential Diagnoses

• Folliculitis.
• Keratosis pilaris.
• Milia.
• Miliaria.
• Neonatal cephalic pustulosis.

Severity Classification

Mild Acne

• Primarily composed of noninflammatory lesions or comedones (blackheads or whiteheads).
• Some papules (red pimples) may also be present.

Moderate Acne

• Contains both noninflammatory comedones and inflammatory lesions, including papules and a few pustules (pimples with a white top).

Moderate to Severe Acne

• Characterized by numerous comedones, pustules, and papules.
• A few cysts (large pus-filled inflammatory lesions >5 mm in diameter) or nodules (cysts that have ruptured) may also be present.

Severe Acne

• Characterized by both inflammatory and noninflammatory symptoms as described above, but with the presence of numerous nodules and/or cysts.
• Nodules and cysts are often painful and found on the face, neck, and upper trunk, and sometimes extend to the waistline.

Treatment

Identification of Acne Severity

• Determined by specific clinical features and lesion types.
• Severity guides the most appropriate treatment.

Considerations Before Treatment

• Acne can indicate androgenisation in women.
• Evaluate for hirsutism, obesity, menstrual irregularity; consider endocrine evaluation.
• Occupational exposures (halogens, industrial oils, hot/humid environments) can aggravate acne.
• Minimize or avoid exposure to aggravating factors.
• Educate patients, dispel common myths.

Psychosocial Assessment

• Acne impacts emotional and social well-being.
• Can lead to social isolation, distorted body image, poor self-confidence, depression, and suicidal ideation.
• Psychosocial impact assessment is crucial regardless of acne severity.
• Use open-ended questions to explore feelings about acne.

General Measures

• Discontinue or change acnegenic drugs.
• Consider switching to combined oral contraceptive pills (COCP) that are antiandrogenic.
• Use non-comedogenic, oil-free creams, cosmetics, and sunscreens.

Mild Acne

• Treat even mild forms of acne.
• Topical monotherapy:
  • Salicylic acid
  • retinoids
  • benzoyl peroxide (BPO)
  • Add topical antibiotic after 6 weeks if no improvement, alongside BPO to prevent antibiotic resistance.

Moderate Acne

• Oral Antibiotics.
• COCP and/or spironolactone for females.
• Combination therapy with a topical retinoid or a topical combination.

Severe Acne

• Refer for oral isotretinoin if other treatments are ineffective or if acne is severe with marked negative emotional/social effects.
• Topical antibiotics.

Specific Treatments

Over-the-Counter Products:

• Benzoyl Peroxide: Available in 2.5%, 5%, and 10% concentrations. Start with 5%, or 2.5% for sensitive skin. It’s antibacterial and can bleach fabric.
• Salicylic Acid: Concentrations vary. It’s a keratolytic agent, helping to unblock pores.
• Azelaic Acid
• Niacinamide

Benzoyl Peroxide

• 5% concentration.
• First-line for mild acne.
• Available as cream or wash.
• Can bleach colored fabrics.

Clindamycin

• 1% concentration.
• Less irritating than benzoyl peroxide.
• Synergistic when combined with benzoyl peroxide.

Role of Antibiotics

• Propionibacterium acnes plays a key role in acne pathogenesis.
• Suppress P. acnes with oral or topical antibiotics, crucial for moderate to severe acne.
• Topical clindamycin and erythromycin are effective.
• Oral antibiotics: doxycycline preferred; minocycline limited by tolerability.
• Tetracyclines contraindicated in children and pregnancy; counsel on sun exposure.
• Oral erythromycin for patients who can’t take tetracyclines.
• Review therapy efficacy after 6-8 weeks; switch antibiotics if no improvement.
• Discontinue oral antibiotics once acne is controlled; continue topical treatment for 3-6 months for maintenance.
• Avoid concurrent use of oral and topical antibiotics due to lack of synergy and resistance risk.

Risk of Antibiotic Resistance

• Limited courses and responsible use of antibiotics advised.
• Increased prevalence of resistance, especially to erythromycin and clindamycin.
• Use BPO with antibiotics to prevent resistance.

Concurrent Use of BPO and Antibiotics

• BPO addition prevents bacterial resistance development.
• Recommended from the beginning of treatment.
• No evidence that topical retinoids prevent antibiotic resistance.

Topical Retinoids

• Adapalene (Differin) 0.1% cream/gel: Apply once daily at night. Increase frequency gradually.
• Tretinoin (Retin-A) 0.025% cream: Apply once daily at night. Increase strength if tolerated and needed.
• Trifarotene 0.005% cream: Specifically approved for acne on the trunk.
• .Teratogenic; use with caution.
• Initial application every other night, then every night.
• Use low-irritant, pH-balanced, soap-free cleanser.
• If inadequate improvement after 6 weeks, change to a topical combination or a higher strength.

Topical Combinations

• Benzoyl peroxide + adapalene for comedonal acne.
• Benzoyl peroxide + clindamycin for inflammatory acne.
• Cease use when inflammation has improved.

Oral Antibiotics

• Doxycycline: 50 to 100 mg daily.
• Minocycline: 50 to 100 mg daily.
• Oral Erythromycin: 250-500 mg twice daily. Useful if tetracyclines are contraindicated.
• Review after 6 weeks.
• Check liver function tests (LFTs) prior and every 12 months if using minocycline.
• Contraindicated in pregnancy (use erythromycin instead).

Combined Oral Contraceptive Pills (COCP)

• Effect may take 3-6 months.
• Cyproterone is most likely to improve acne.
• If not tolerated, alternatives include desogestrel, drospirenone, and gestodene.
• Can be combined with oral antibiotics or spironolactone.

Spironolactone – Antiandrogens (For Female Patients))

• Start at 25-50 mg/day
• can increase to 50-100 mg/day
• Monitor
  • blood pressure
  • kidney function
  • LFTs every 6 months.
  • menstrual irregularities and breast tenderness.
• Contraindicated in pregnancy due to risk of defective virilization.
• COCP should be added for contraception and to minimize adverse effects.
• Side effects: polyuria, postural hypotension.

Oral Isotretinoin

• treatment of choice for acne with
  • severe and cystic or scarring
  • resistant to other treatments
  • persistently relapses
  • marked negative emotional and social effect on the patient
• Typical initial dose is 0.5 mg/kg/day, can go up to 1 mg/kg/day
• Treatment duration usually 6-9 months.
• Oral isotretinoin is a potent teratogen and is contraindicated in pregnancy
• A history of depression is not a contraindication to the use of oral isotretinoin, and patients can be treated for depression and acne at the same time.

Adverse effects of oral isotretinoin

common	early flare of acne sun sensitivity dry lips, eyes and mucosal lining of nose dry skin and dermatitis (especially on forearms) cheilitis nose bleeds facial erythema lethargy myalgia joint stiffness
less common	paronychia impaired night vision rectal bleeding dyslipidaemia headache hair loss

Information for patients with acne

• Myths about acne
  • Acne is caused by a poor diet.
    • False. Diet does not generally affect acne, although many people think that chocolate makes their acne worse. Some evidence suggests that dairy products and high glycaemic index foods aggravate acne (but don’t cause it). If you think certain foods make your acne worse, avoid them.
  • Acne is caused by a hormone imbalance.
    • Most people with acne have normal hormone levels, but their skin is more sensitive to the hormones. In a minority of people (eg people with polycystic ovary syndrome [PCOS]), acne is related to a hormone imbalance.
  • Acne is caused by poor hygiene.
    • False. Although general hygiene (eg daily face-washing) can help manage acne, acne is not caused by poor hygiene, and washing too much can make it worse. Oily skin is genetic, and not because you don’t wash enough.
  • All teenagers have acne, so it doesn’t matter.
    • 50% of teenagers have acne, and it does matter a lot to them. No-one wants to look in the mirror and see spots, and even if your friends have acne too, this doesn’t make it easier.
• Truths about acne
  • Acne is common.
  • Acne can start from the age of 8 years.
  • Acne can cause embarrassment, anxiety, social withdrawal and depression.
  • Oily skincare products and cosmetics make acne worse.
  • Saunas make acne worse.
  • Some people don’t ‘grow out’ of acne.
  • Acne can cause permanent scarring.
  • Acne can be controlled with medication.
• How to treat acne
  • Use your prescribed treatment every day, unless directed otherwise.
  • Apply creams to the whole affected area, not just to the spots.
  • Use water-based or oil-free cosmetics and sunscreens.
  • Use a light moisturiser.
  • Try not to pick and squeeze the spots, because this causes scabs that make the skin look worse and may increase likelihood of scarring.
  • Be patient—most treatments take at least 6 to 12 weeks to work.

Special Considerations

Infantile Acne

• Can occur after 3 months of age.
• Needs comedones, papules, and pustules.
• Usually mild and resolves by 12 months.
• Treatment options include benzoyl peroxide, topical antibiotics, and topical retinoids.

Neonatal Cephalic Pustulosis

• Variant of neonatal acne.
• Eruption on the face and/or scalp of newborn babies, usually around 3 weeks of age.
• No comedones present.
• Associated with Malassezia colonization.
• Usually resolves without treatment.
• Can use topical antifungals, e.g., Ketoconazole 2% BD for 3 days.