What is the recommended first-line treatment regimen for mild to moderate acne?

First-Line Treatment for Mild to Moderate Acne

Begin all patients with mild to moderate acne on a fixed-dose combination of adapalene 0.1-0.3% plus benzoyl peroxide 2.5-5% applied once daily in the evening as the foundational regimen. 1

Treatment Algorithm by Acne Severity

Mild Acne (Predominantly Comedonal)

• Start with topical retinoid (adapalene preferred) combined with benzoyl peroxide as first-line therapy. 1
• Adapalene 0.1% is available over-the-counter, making it highly accessible, and can be applied with benzoyl peroxide without oxidation concerns or photolability restrictions. 1
• This combination addresses both comedones and microcomedones (the precursor lesions) while providing antimicrobial activity. 1
• Apply once daily in the evening after washing and allowing skin to dry for 20-30 minutes, using a pea-sized amount for each facial area (forehead, chin, each cheek). 1

Moderate Acne (Mixed Comedonal and Inflammatory)

• Use the same adapalene-benzoyl peroxide foundation, then add a fixed-dose topical antibiotic combination (clindamycin 1%/benzoyl peroxide 5% or erythromycin 3%/benzoyl peroxide 5%) for inflammatory lesions. 1
• The fixed-combination products enhance treatment compliance and are more effective than either agent alone. 1
• Never use topical antibiotics as monotherapy—this rapidly induces bacterial resistance. 1
• Benzoyl peroxide must always be included when using any antibiotic to prevent resistance development. 1, 2

Application Strategy to Minimize Irritation

• Start with reduced frequency of application (every other night initially) and use concurrent emollients to mitigate initial irritation from retinoids. 1
• Daily sunscreen use is mandatory due to photosensitivity risk from retinoids. 1
• Avoid applying retinoids to broken skin or areas with active wounds. 1

Alternative Topical Options for Specific Situations

• For patients with post-inflammatory hyperpigmentation (especially darker skin tones): Add azelaic acid 15-20%, which provides comedolytic, antibacterial, and anti-inflammatory effects while addressing dyspigmentation. 1
• For adult females with inflammatory acne: Topical dapsone 5% gel is particularly effective and does not require glucose-6-phosphate dehydrogenase testing before initiation. 1
• For patients who cannot tolerate retinoids: Salicylic acid 0.5-2% is an over-the-counter alternative, though it has less robust evidence than adapalene-benzoyl peroxide combinations. 1

When to Escalate Beyond First-Line Topical Therapy

• If no improvement after 6-8 weeks of appropriate topical therapy, escalate treatment based on severity. 3
• For moderate-to-severe inflammatory acne not responding to topicals alone, add oral doxycycline 100 mg once daily (maximum 3-4 months) while continuing the topical retinoid-benzoyl peroxide foundation. 1, 2
• Any evidence of active scarring, regardless of lesion count, warrants consideration of oral isotretinoin. 1, 4
• Significant psychosocial burden or distress also justifies more aggressive treatment, potentially including isotretinoin. 1

Maintenance Therapy After Clearance

• Continue topical retinoid monotherapy (adapalene) indefinitely after achieving clearance to prevent recurrence by addressing microcomedone formation. 1
• Benzoyl peroxide can also be continued as maintenance therapy. 1

Critical Pitfalls to Avoid

• Never prescribe topical antibiotics without concurrent benzoyl peroxide—resistance develops rapidly without it. 1, 2
• Do not apply traditional tretinoin formulations simultaneously with benzoyl peroxide, as oxidation inactivates tretinoin (adapalene does not have this limitation). 1
• Avoid underestimating severity when scarring is present—this warrants more aggressive treatment regardless of lesion count. 1
• Do not use salicylic acid concomitantly with adapalene without caution, as the combination may induce significant local irritation. 1

Hormonal Therapy Considerations for Female Patients

• For females with hormonal acne patterns (premenstrual flares, jaw-line distribution), consider adding spironolactone 50-100 mg daily or combined oral contraceptives to the topical regimen. 1, 4
• Combined oral contraceptives reduce inflammatory lesions by 62% at 6 months and can be used as monotherapy or combined with topical agents. 1
• Spironolactone does not require routine potassium monitoring in healthy patients without risk factors for hyperkalemia. 1, 4