Acne Vulgaris Treatment
Begin all acne patients on topical adapalene 0.1-0.3% combined with benzoyl peroxide 2.5-5% as the foundation, then escalate based on severity by adding topical antibiotics for moderate disease or oral antibiotics (doxycycline 100 mg daily) for moderate-to-severe inflammatory acne, always with concurrent benzoyl peroxide to prevent resistance. 1
Assessment and Severity Classification
Classify acne severity using the Physician Global Assessment (PGA) scale as mild, moderate, or severe 1. Evaluate for:
- Scarring presence (automatically warrants aggressive treatment regardless of lesion count) 1, 2
- Post-inflammatory dyspigmentation 1
- Psychosocial impact and quality of life 1
- Distribution (face, trunk, or both) 3
The presence of scarring alone should classify the patient as having severe acne and makes them a candidate for isotretinoin therapy 2.
Treatment Algorithm by Severity
Mild Acne
- First-line: Topical retinoid (adapalene 0.1-0.3% preferred) + benzoyl peroxide 2.5-5% 1
- Apply once daily in the evening to completely dry skin 1
- Adapalene is preferred over tretinoin because it can be applied simultaneously with benzoyl peroxide without oxidation concerns and lacks photolability restrictions 1, 4
- Adapalene 0.1% is available over-the-counter 1
Alternative options:
- Azelaic acid 15-20% for patients with post-inflammatory hyperpigmentation 1
- Topical dapsone 5% gel, particularly effective for inflammatory acne in adult females (no G6PD testing required) 1
Moderate Acne
- First-line: Fixed-dose combination of topical retinoid + benzoyl peroxide 1
- Add: Topical antibiotic (clindamycin 1% or erythromycin 3%) combined with benzoyl peroxide for inflammatory lesions 1
- Fixed-combination products (clindamycin 1%/BP 5%, clindamycin 1%/BP 3.75%, erythromycin 3%/BP 5%) enhance compliance 1
Critical: Never use topical antibiotics as monotherapy—always combine with benzoyl peroxide to prevent bacterial resistance 1, 5.
Moderate-to-Severe Inflammatory Acne
- First-line triple therapy: Oral antibiotics + topical retinoid + benzoyl peroxide 1
- Strongly recommended: Doxycycline 100 mg once daily (moderate evidence) 1
- Conditionally recommended: Minocycline 100 mg once daily (moderate evidence) 1
- Alternative: Sarecycline (newer tetracycline option) 1
- Limit systemic antibiotics to 3-4 months maximum to minimize bacterial resistance 1, 4
Subantimicrobial dosing of doxycycline (20 mg twice daily to 40 mg daily) has shown efficacy in moderate inflammatory acne 1.
Severe Nodular or Recalcitrant Acne
Isotretinoin is indicated for: 1, 2
- Severe nodular or conglobate acne
- Treatment-resistant moderate acne after 3-4 months of appropriate therapy
- Any acne with scarring or significant psychosocial burden
Dosing: 0.5-1.0 mg/kg/day targeting cumulative dose of 120-150 mg/kg 1. Daily dosing is preferred over intermittent dosing 1.
Monitoring requirements:
- Liver function tests and lipids only 1
- CBC monitoring is not needed in healthy patients 1
- No routine monitoring for depression or inflammatory bowel disease (population studies have not identified increased risk) 1
- Mandatory pregnancy prevention through iPledge program for persons of childbearing potential 1, 4
Adjunctive therapy for severe acne:
- Intralesional triamcinolone acetonide 2.5-10 mg/mL for large, painful nodules (provides rapid relief within 48-72 hours) 1, 4, 2
- Oral corticosteroids can provide temporary benefit while starting standard therapy 1
Hormonal Therapy for Female Patients
Combined Oral Contraceptives
- Reduce inflammatory lesions by 62% at 6 months 1, 3
- Can be used as monotherapy or combined with topical agents 1
- Conditionally recommended by the American Academy of Dermatology 1
Spironolactone
- Dosing: 25-200 mg daily 1, 4
- Particularly useful for hormonal acne patterns, premenstrual flares, or those who cannot tolerate oral antibiotics 1, 4
- No potassium monitoring needed in healthy patients without risk factors for hyperkalemia 1
- Excellent option for long-term maintenance without the 3-4 month limitation of oral antibiotics 4
Maintenance Therapy After Clearance
Continue topical retinoid indefinitely after achieving clearance to prevent recurrence 1, 4. Reduce to 2-3 times weekly for long-term maintenance 4.
Benzoyl peroxide can be continued as maintenance therapy 1, 4.
Critical Pitfalls to Avoid
- Never use topical or oral antibiotics as monotherapy—resistance develops rapidly without concurrent benzoyl peroxide 1, 4, 2
- Never extend oral antibiotics beyond 3-4 months without re-evaluation (dramatically increases resistance risk) 1, 4
- Do not underestimate severity when scarring is present—this warrants aggressive treatment 1, 2
- Avoid applying tretinoin with benzoyl peroxide simultaneously (oxidation inactivates tretinoin) 1
- Do not use oral antibiotics as primary therapy for acne conglobata—they are inadequate and delay definitive isotretinoin treatment 1
- Recommend daily sunscreen use with retinoids due to photosensitivity risk 1
Special Populations
Preadolescent Children
Topical adapalene, tretinoin, and benzoyl peroxide can be safely used 1.
Pregnant Patients
Azelaic acid is safer (pregnancy category B) compared to retinoids (category C) or tazarotene (category X) 1.
Patients with Psychiatric Comorbidities
Start with topical adapalene 0.3% gel combined with benzoyl peroxide 5%, avoiding systemic antibiotics and deferring isotretinoin until psychiatric stability is established 4.