Treatment of Acne Vulgaris by Type and Severity
Severity Assessment
All patients with acne should be assessed using the Physician Global Assessment (PGA) or other standardized scales to consistently classify severity and guide treatment selection. 1, 2 Evaluate for scarring, post-inflammatory dyspigmentation, and psychosocial impact, as these factors warrant more aggressive treatment regardless of lesion count. 2
Mild Acne (Predominantly Comedonal or Minimal Inflammatory Lesions)
First-line treatment: Topical retinoid (adapalene 0.1-0.3% preferred) combined with benzoyl peroxide 2.5-5%. 1, 2
Why This Combination Works:
- Adapalene addresses comedones and microcomedones while providing anti-inflammatory effects 2
- Benzoyl peroxide provides antimicrobial activity without risk of bacterial resistance 2
- This combination is more effective than either agent alone, with 21-47% successful treatment rates in clinical trials 2
Application Instructions:
- Apply once daily in the evening after washing and allowing skin to dry for 20-30 minutes 2
- Use a pea-sized amount for each facial area (forehead, chin, each cheek) 2
- Start with lower concentrations and less frequent application if irritation occurs 3
Alternative Options:
- Azelaic acid for patients with post-inflammatory dyspigmentation (particularly useful for darker skin tones) 2
- Salicylic acid 0.5-2% as an over-the-counter option, though evidence is less robust than for adapalene/benzoyl peroxide 2
Special Populations:
- Children under 12 years: Benzoyl peroxide 2.5% is the primary treatment 3
- Children ≥9 years: Adapalene 0.1% gel may be added for predominantly comedonal acne 3
- Pregnant patients: Azelaic acid (pregnancy category B) is safer than retinoids 2
Moderate Acne (Mixed Comedonal and Inflammatory Lesions)
First-line treatment: Fixed-dose combination of topical retinoid + benzoyl peroxide, with addition of topical antibiotic (clindamycin 1% or erythromycin 3%) for inflammatory lesions. 1, 2
Critical Rule:
Never use topical antibiotics as monotherapy—always combine with benzoyl peroxide to prevent bacterial resistance. 1, 2 Fixed-dose combination products (clindamycin 1%/benzoyl peroxide 5% or 3.75%, erythromycin 3%/benzoyl peroxide 5%) enhance compliance and efficacy. 1, 2
Application Strategy:
- Apply fixed-dose combination once daily in the evening 2
- Continue topical retinoid as the foundation of therapy 2
Alternative Topical Options:
- Topical dapsone 5% gel is particularly effective for inflammatory acne in adult females 2
- No glucose-6-phosphate dehydrogenase testing required before starting topical dapsone 2
Adjunctive Treatment:
- Intralesional triamcinolone acetonide 10 mg/mL for larger nodules at risk of scarring provides rapid pain relief and inflammation reduction within 48-72 hours 1, 2
Moderate-to-Severe Acne (Extensive Inflammatory Lesions)
First-line treatment: Oral antibiotics + topical retinoid + benzoyl peroxide (triple therapy). 1, 2
Oral Antibiotic Selection:
- Doxycycline 100 mg once daily (strongly recommended with moderate evidence) 1, 2
- Minocycline 100 mg once daily (conditionally recommended as alternative) 1, 2
- Sarecycline (newer tetracycline option with dosing based on weight) 2
- Tetracyclines are contraindicated in children <8 years due to permanent tooth discoloration risk 3
Critical Duration Limits:
Limit systemic antibiotics to 3-4 months maximum to minimize bacterial resistance development. 1, 2 After this period, transition to topical retinoid monotherapy for maintenance. 2
Mandatory Combination:
Always use benzoyl peroxide concurrently with oral antibiotics to prevent resistance. 1, 2 Continue topical retinoid as the foundation throughout treatment. 2
Subantimicrobial Dosing Option:
Doxycycline 20 mg twice daily to 40 mg daily has shown efficacy for moderate inflammatory acne with potentially reduced resistance risk. 2
Severe Nodular or Cystic Acne
Isotretinoin is the definitive treatment and should be initiated immediately for severe acne, as it is the only drug affecting all four pathogenic factors of acne. 1, 2, 4
Indications for Isotretinoin:
- Severe nodular or conglobate acne 1, 2
- Treatment-resistant moderate acne after 3-4 months of appropriate therapy 2
- Any acne with scarring or significant psychosocial burden 1, 2
Dosing:
- Standard dosing: 0.5-1.0 mg/kg/day targeting cumulative dose of 120-150 mg/kg 2
- Daily dosing preferred over intermittent dosing 1, 2
- Either lidose-isotretinoin or standard isotretinoin formulations are acceptable 1, 2
- Must be taken with food to increase bioavailability 5
Required Monitoring:
- Monitor only liver function tests and lipids 1, 2
- CBC monitoring is not needed in healthy patients 2
- Population-based studies have not identified increased risk of neuropsychiatric conditions or inflammatory bowel disease 1, 2
Mandatory Pregnancy Prevention:
For persons of pregnancy potential, pregnancy prevention is mandatory through the iPledge program. 1, 2, 6 Isotretinoin is pregnancy category X with near-universal teratogenicity. 5
Adjunctive Therapy During Isotretinoin:
- Oral corticosteroid therapy can provide temporary benefit in severe inflammatory acne while starting isotretinoin 2
- Intralesional triamcinolone for individual large, painful nodules 2
Hormonal Acne (Female Patients)
For female patients with hormonal patterns (premenstrual flares, jawline distribution, signs of hyperandrogenism), hormonal therapy is highly effective. 1, 2, 7
First-Line Hormonal Options:
Combined oral contraceptives (COCs):
- Reduce inflammatory lesions by 62% at 6 months 2
- Can be used as monotherapy or combined with topical agents 2
- Conditionally recommended by the American Academy of Dermatology 2
Spironolactone 25-200 mg daily:
- First-choice oral anti-androgen therapy 7
- Starting dose typically 50-100 mg daily 7
- Useful for patients who cannot tolerate or prefer to avoid oral antibiotics 2
- No potassium monitoring needed in healthy patients without risk factors for hyperkalemia 1, 2, 7
When to Consider Endocrine Testing:
Patients with clinical signs of hyperandrogenism (hirsutism, oligomenorrhea, androgenic alopecia, infertility, clitoromegaly, truncal obesity) warrant endocrine testing including free and total testosterone, DHEA-S, LH, and FSH. 1, 7
Maintenance Therapy After Clearance
Continue topical retinoid monotherapy indefinitely after achieving clearance to prevent recurrence. 1, 2 Benzoyl peroxide can also be continued as maintenance therapy. 2
Critical Pitfalls to Avoid
- Never use topical or oral antibiotics as monotherapy—resistance develops rapidly without concurrent benzoyl peroxide 1, 2
- Never extend oral antibiotics beyond 3-4 months without re-evaluation, as this dramatically increases resistance risk 1, 2
- Do not underestimate severity when scarring is present—this warrants more aggressive treatment regardless of lesion count 2
- Do not apply traditional tretinoin formulations with benzoyl peroxide simultaneously—oxidation inactivates tretinoin 2
- Do not delay isotretinoin in severe acne—oral antibiotics are inadequate for acne conglobata and delay definitive treatment 2