What is the first-line treatment for acne?

First-Line Treatment for Acne Vulgaris

Begin with a topical retinoid (adapalene 0.1-0.3% or tretinoin 0.025-0.1%) combined with benzoyl peroxide 2.5-5% as first-line therapy for mild to moderate acne. 1

Treatment Algorithm Based on Severity

Mild Acne (Predominantly Comedonal)

• Start with topical retinoid + benzoyl peroxide combination 1
• Topical retinoid options include:
  • Adapalene 0.1% gel (available over-the-counter, making it highly accessible) 1, 2
  • Tretinoin 0.025-0.1% (cream, gel, or microsphere gel) 1
  • Tazarotene 0.05-0.1% (cream, gel, or foam) 1
  • Trifarotene (newer option) 1
• Apply benzoyl peroxide 2.5-5% concurrently (lower concentrations cause less irritation while maintaining efficacy) 1
• Alternative for patients with post-inflammatory hyperpigmentation: Add azelaic acid 1

Moderate Acne (Mixed Comedonal and Inflammatory)

• Use fixed-dose combination of topical retinoid + benzoyl peroxide as foundation 1
• Add topical antibiotics (clindamycin 1% or erythromycin 3%) ONLY in combination with benzoyl peroxide—never as monotherapy 1
• Fixed-combination products enhance compliance: erythromycin 3%/BP 5%, clindamycin 1%/BP 5%, or clindamycin 1%/BP 3.75% 1
• For adult females with inflammatory acne: Consider topical dapsone 5% gel (no G6PD testing required for topical formulation) 1

Moderate-to-Severe Acne (Predominantly Inflammatory)

• Triple therapy: oral antibiotics + topical retinoid + benzoyl peroxide 1
• First-line oral antibiotics:
  • Doxycycline 100 mg once daily 1
  • Minocycline 100 mg once daily 1
  • (Both are superior to tetracycline) 1
• Critical: Limit systemic antibiotics to 3-4 months maximum to prevent resistance 1
• Always use benzoyl peroxide concurrently with oral antibiotics to prevent bacterial resistance 1

Mechanism-Based Rationale

The combination approach targets all four pathogenic factors simultaneously 1:

• Topical retinoids: Resolve microcomedones (precursor lesions), provide comedolytic and anti-inflammatory effects 1
• Benzoyl peroxide: Kills Cutibacterium acnes through free oxygen radical release with no reported bacterial resistance 1
• Antibiotics (when needed): Reduce inflammatory lesions and bacterial load 1

Special Population Considerations

Female Patients with Hormonal Component

• Combined oral contraceptives are effective for inflammatory acne 1
• Spironolactone is useful for those with hormonal acne patterns or who cannot tolerate/prefer to avoid oral antibiotics 1

Preadolescent Children

• Topical adapalene, tretinoin, and benzoyl peroxide can be safely used 1

Maintenance Therapy After Clearance

Continue topical retinoid monotherapy indefinitely to prevent recurrence 1

• Benzoyl peroxide can also be continued as maintenance 1
• This prevents reformation of microcomedones that lead to relapse 1

Critical Pitfalls to Avoid

• NEVER use topical or oral antibiotics as monotherapy—resistance develops rapidly without concurrent benzoyl peroxide 1
• Do not extend oral antibiotics beyond 3-4 months without re-evaluation, as this dramatically increases resistance risk 1
• Do not stop treatment once acne clears—maintenance with topical retinoids is essential 1
• Do not underestimate severity when scarring is present—this warrants more aggressive treatment 1
• Apply tretinoin formulations in the evening due to photolability; do not combine with benzoyl peroxide at the same time 1
• Warn patients that benzoyl peroxide bleaches clothing and bedding 3
• Recommend daily sunscreen use with topical retinoids due to photosensitivity 1

Practical Application Tips

• Start with lower concentrations of both retinoids and benzoyl peroxide to minimize irritation, then titrate up as tolerated 1
• Fixed-combination products reduce the number of applications and improve adherence 1
• Assess quality of life impact and presence of scarring, as these may warrant escalation of therapy 1
• Use standardized scales like Physician Global Assessment (PGA) to consistently evaluate severity 1