Role of Azelaic Acid in Treating Acne
Azelaic acid is an effective topical treatment for mild to moderate acne vulgaris, offering multiple beneficial mechanisms including antimicrobial, anti-inflammatory, and comedolytic properties with a favorable safety profile. 1
Mechanism of Action
Azelaic acid works through multiple mechanisms to treat acne:
- Antimicrobial activity against Propionibacterium acnes and Staphylococcus epidermidis, likely through inhibition of microbial cellular protein synthesis 2
- Normalization of keratinization leading to an anticomedonal effect 2
- Anti-inflammatory properties that help reduce inflammatory acne lesions 1
- Antioxidant properties and inhibition of reactive oxygen species production by neutrophils 3
Clinical Efficacy
- In clinical trials, azelaic acid 20% cream demonstrated significant efficacy, with 28% more patients achieving 50-100% reduction in total lesion count compared to vehicle at 3 months 1
- Studies have shown that 20% azelaic acid cream can reduce total lesion count by 60.6% compared to 19.9% with placebo 4
- Azelaic acid gel was found to be 3.06 times more effective than placebo in reducing acne severity index (ASI) 4
Formulations and Administration
- Azelaic acid is available as a 20% cream formulation for acne treatment 1
- A thin film should be gently but thoroughly massaged into affected areas twice daily, in the morning and evening 1
- Approximately 3-5% of applied azelaic acid penetrates into the stratum corneum, with up to 10% found in the epidermis and dermis 2
- Only about 4% of topically applied azelaic acid is systemically absorbed 2
Comparative Efficacy
- Azelaic acid has demonstrated comparable anti-acne efficacy to other first-line topical treatments including:
- Tretinoin (0.05%)
- Benzoyl peroxide (5%)
- Topical erythromycin (2%) 5
- The American Academy of Dermatology recommends azelaic acid as an effective adjunctive acne treatment, particularly for post-inflammatory dyspigmentation 6
Special Considerations and Advantages
- Particularly beneficial for patients with sensitive skin or darker skin types (Fitzpatrick IV or greater) due to its lightening effect on post-inflammatory hyperpigmentation 6, 1
- Classified as pregnancy category B, indicating minimal risk during pregnancy 6, 1
- Does not induce bacterial resistance, unlike topical antibiotics 5
- Well-tolerated with excellent local tolerability and is not associated with systemic adverse events or photodynamic reactions 5
Side Effects and Safety
- Common side effects include pruritus, burning, stinging, tingling, erythema, dryness, rash, peeling, irritation, and contact dermatitis 1
- Side effects are generally mild and transient 5
- Long-term use has not shown toxic or allergic reactions 7
Recommendations for Use
- Recommended as monotherapy for mild acne or in combination with other agents for moderate to severe acne 6
- Can be used as maintenance therapy following discontinuation of systemic therapy to reduce recurrences 5
- May be combined with systemic antibiotics like minocycline for moderate to severe acne with excellent results (90% good and excellent results reported) 5
- Particularly useful in patients who cannot tolerate other topical acne treatments due to irritation 1
Clinical Pearls
- Azelaic acid takes time to show its full effect, with progressive improvement over several weeks of consistent use 7
- Patient education about potential initial mild irritation can improve adherence to treatment 1
- The dual benefit of treating both acne and post-inflammatory hyperpigmentation makes it especially valuable for patients with darker skin types 6, 1