Acne vulgaris · House

Red Flags

Acne fulminans (sudden severe nodulocystic with fever, arthralgia, malaise) — admit; oral steroid before isotretinoin; rare but serious^[1]
Pregnancy or planning pregnancy on isotretinoin — absolutely contraindicated; pregnancy prevention programme; switch to alternatives^[1]
Severe persistent psychological impact, suicidal ideation — mental health support; counsel about isotretinoin and mood (rare association)^[1]
Acne with virilising features (hirsutism, oligomenorrhoea, alopecia) in young women — investigate for PCOS, late-onset CAH, androgen-secreting tumour^[1]

First-line treatment

Interventions

General skin care^[1]
Gentle non-comedogenic cleanser BD; sunscreen SPF ≥30 daily (essential for PIH prevention); avoid harsh scrubs and over-cleansing; non-comedogenic cosmetics
Mild acne — topical combination^[1]
Topical retinoid (adapalene, tretinoin) + benzoyl peroxide (BPO 2.5–5%); apply once daily at night; expect initial pustular flare and dryness; full effect 8–12 weeks
Moderate acne — oral antibiotic + topical^[1]
Doxycycline 100 mg PO daily × 3 months max + topical retinoid + BPO; avoid antibiotic monotherapy (resistance); macrolide alternative if doxycycline contraindicated
Severe/nodulocystic acne — isotretinoin^[1]
Oral isotretinoin 0.5–1 mg/kg/day to cumulative 120–150 mg/kg over 4–6 months; pregnancy prevention programme; LFT, lipids, FBC at baseline and 1–2 monthly
Hormonal therapy in selected women^[1]
Combined oral contraceptive (containing drospirenone or norgestimate) ± spironolactone 50–100 mg daily; useful in adult women with hormonal pattern, PCOS, or contraindication to isotretinoin
Post-inflammatory hyperpigmentation management^[1]
Strict sun protection; topical retinoid (adapalene); azelaic acid 15–20%; tranexamic acid topical; chemical peels (glycolic, salicylic, mandelic) at specialist; avoid hydroquinone monotherapy long-term

First-line drug therapy

Drug	Class	Adult	Paediatric	Notes
Adapalene 0.1% gel (topical retinoid)^[1]	Topical retinoid	Apply pea-sized amount once daily at night to affected areas	≥9 years per local label	First-line topical for mild acne and maintenance; less irritation than tretinoin; safe in skin of colour; sun protection essential
Benzoyl peroxide 2.5–5% gel^[1]	Topical antimicrobial	Apply once or twice daily	≥12 years	Reduces P. acnes resistance when combined with antibiotic; bleaches fabric; mild irritation; combine with retinoid
Doxycycline (oral)^[1]	Tetracycline antibiotic	100 mg PO daily × 3 months maximum	≥8 years: 1 mg/kg/day; ≥12 years: 100 mg daily	First-line oral antibiotic for moderate acne; photosensitivity — sunscreen counselling; oesophageal irritation — take with water and upright; combine with topical retinoid + BPO; never as monotherapy
Isotretinoin (oral)^[1]	Oral retinoid	0.5–1 mg/kg/day to cumulative 120–150 mg/kg over 4–6 months	Per dermatologist	Severe/nodulocystic or refractory acne; severe teratogenicity — pregnancy prevention programme; LFT/lipids monitoring; mucocutaneous side effects; counsel about mood
Spironolactone (women)^[1]	Aldosterone antagonist	50–100 mg PO daily titrated to 200 mg	—	Adult women with hormonal pattern; pregnancy contraindicated (anti-androgen feminisation of male fetus); potassium and BP monitoring

Adapalene 0.1% gel (topical retinoid)^[1]

Topical retinoid

Adult: Apply pea-sized amount once daily at night to affected areas
Paediatric: ≥9 years per local label

First-line topical for mild acne and maintenance; less irritation than tretinoin; safe in skin of colour; sun protection essential

Benzoyl peroxide 2.5–5% gel^[1]

Topical antimicrobial

Adult: Apply once or twice daily
Paediatric: ≥12 years

Reduces P. acnes resistance when combined with antibiotic; bleaches fabric; mild irritation; combine with retinoid

Doxycycline (oral)^[1]

Tetracycline antibiotic

Adult: 100 mg PO daily × 3 months maximum
Paediatric: ≥8 years: 1 mg/kg/day; ≥12 years: 100 mg daily

First-line oral antibiotic for moderate acne; photosensitivity — sunscreen counselling; oesophageal irritation — take with water and upright; combine with topical retinoid + BPO; never as monotherapy

Isotretinoin (oral)^[1]

Oral retinoid

Adult: 0.5–1 mg/kg/day to cumulative 120–150 mg/kg over 4–6 months
Paediatric: Per dermatologist

Severe/nodulocystic or refractory acne; severe teratogenicity — pregnancy prevention programme; LFT/lipids monitoring; mucocutaneous side effects; counsel about mood

Spironolactone (women)^[1]

Aldosterone antagonist

Adult: 50–100 mg PO daily titrated to 200 mg
Paediatric: —

Adult women with hormonal pattern; pregnancy contraindicated (anti-androgen feminisation of male fetus); potassium and BP monitoring

Safety-net

Allow at least 8–12 weeks for treatment to show effect; do not switch prematurely or stack multiple irritants^[1]
Use sunscreen daily — sun exposure worsens post-inflammatory hyperpigmentation, the most common cosmetic concern in skin of colour^[1]
On isotretinoin: report mood changes, severe headache, abdominal pain, vision changes, or hearing changes immediately; absolute contraception^[1]

Referral criteria

Severe nodulocystic acne, scarring, or refractory to combined topical + oral antibioticDermatology for isotretinoin consideration^[1]
Acne fulminans or systemic featuresDermatology admission and pre-isotretinoin oral steroid^[1]
Suspected hyperandrogenism (hirsutism, oligomenorrhoea, virilisation)Endocrinology / gynaecology workup^[1]
Pregnancy planning while on isotretinoin or oral antibioticJoint dermatology and obstetric pre-conception clinic; switch to safer alternatives^[1]

Clinical summary

Severity-graded topical, oral, and isotretinoin-based management of acne vulgaris in adolescents and adults; pigmentation considerations.

References

1.IADVL Guidelines for Acne Vulgaris Treatment (2023); AAD Acne Vulgaris Management; Global Alliance to Improve Outcomes in Acne (2023)