J. Rao, MD, FRCPC
Division of Dermatology and Cutaneous Sciences, University of Alberta, Edmonton, Canada
- Acne vulgaris is a complex skin disorder of the pilosebaceous unit affecting almost all people at some point in their lifetime, especially among people aged 15–24 years.
- Acne can be physically and emotionally scarring, causing significant psychosocial morbidity and reducing self esteem.
- All forms of acne involve one or more of these pathophysiologic factors:
- Hyperkeratinization of the follicular epithelium with comedone formation
- Increased sebum production
- Bacterial proliferation of Propionibacterium acnes (P. acnes)
- Local immune hypersensitivity causing inflammation.
- Acne may be classified according to predominance of specific skin lesions:
- Comedonal (non-inflammatory) – mild
- Papular (inflammatory) – mild-to-moderate
- Pustular (inflammatory) – moderate
- Nodulocystic – severe
- This order also follows increasing severity, with cutaneous scarring as the ultimate result.
Make a Diagnosis
Existing therapies for acne can be divided into one of the following categories:
- Physical or mechanical modalities
- Includes comedone extraction and other forms of acne surgery, chemical peels, and microdermabrasion.
- Light-based therapy
- Includes laser treatment, the usage of noncoherent light sources and photodynamic therapy
- Topical or systemic medications
- Includes retinoids, antibiotics, benzoyl peroxide, and hormonal therapy.
- Two major categories based on primary mechanism of action:
- Antimicrobials: reduce P. acnes growth
- Comedolytics: reduce and/or prevent comedone formation
- Formulations (i.e., gel vs. cream) may decrease sebum production.
- It is necessary to address all pathophysiologic factors of acne for effective treatment.
- Most medications do not act against all four major pathophysiologic features of acne.
- Combination therapy with a few logically chosen agents has a greater chance of addressing more pathophysiologic factors in acne development.
- Other benefits of combination therapy:
- Some combinations have demonstrated synergy (i.e., the combined effect is better than that seen by the individual agents).
- Potential to decrease individual drug doses and exposure times
- Potential to reduce and prevent antibiotic resistance
- Potential cost-savings by reducing the use of expensive medications.
Recommendations for Treatment
- Topical and systemic agents are the mainstay of acne therapy and maintenance.
- Physical and light-based modalities should be used as second-line or adjunctive therapy.
- Hormonal therapies may be used as second choice or adjunctive therapy in women with contributing androgenic factors for acne.
- Choose agents with different, but complementary mechanisms of action (e.g., antimicrobial + comedolytic agent).
- Tolerability is related to compliance; choose agents with a good tolerability profile.
- Topical retinoids alone, or in combination with other medications, should be considered first-line therapy for both inflammatory and non-inflammatory acne.
- Includes adapalene, tazarotene, tretinoin, and tretinoin gel microsphere.
- Use early for best results.
- Inhibits microcomedone formation, which is the precursor lesion in acne.
- Clears mature comedones.
- Improves inflammatory lesions.
- Has synergistic effects with oral or topical antibiotics.
- Induces remission of acne in maintenance therapy.
- Antibiotics are adjunctive therapy in inflammatory acne.
- Oral antibiotics include minocycline, doxycycline, tetracycline, trimethoprim-sulfamethoxazole, and erythromycin.
- Topical antibiotics include clindamycin and erythromycin.
- Use only as long as necessary and combine with topical retinoids.
- Antibiotics should not be used as monotherapy in order to prevent resistance and target more pathophysiologic factors.
- Minimize duration of therapy to prevent resistance and side-effects.
- If there is need to continue antimicrobials, use benzoyl peroxide or benzoyl peroxide/antibiotic combinations.
|mild acne (comedonal)||• Topical retinoid|
|mild acne (papular)||• Topical retinoid + topical antibiotic +/- benzoyl peroxide|
|moderate acne (papular/pustular)||• Topical retinoid + oral antibiotic +/- benzoyl peroxide|
• Topical retinoids act in synergy with antibiotic to hasten resolution of inflammatory lesions.
• Avoid antibiotic monotherapy.
• Discontinue antibiotic when inflammatory lesions resolve (usually no more than 6 months).
• Use topical retinoid to maintain remission post antibiotic.
|severe acne (nodulocystic)||• Oral isotretinoin|
|Table 1: Treatment options for different acne types.|
Recommendations for Maintenance
|mild-to-moderate acne||• Topical retinoid|
|moderate-to-severe acne||• Topical retinoid +/- benzoyl peroxide|
|Table 2: Recommended maintenance for acne.|
Acne Medications and Pregnancy
Some acne medications must not be used by women who
are pregnant or lactating, or who may become pregnant
because of the potential harm to a fetus or breastfed infant.
These medications include:
- Hormonal therapy
- Estrogen and derivatives, flutamide, spironolactone
Oral and topical isotretinoin
- Established teratogenicity
- Tetracycline, doxycycline, minocycline
- Dental discoloration noted
- Theoretical risk of teratogenicity, anemia, jaundice
- Adapalene, tazarotene, tretinoin
- Theoretical risk of teratogenicity
Acne vulgaris remains a therapeutic challenge, in large part due to its multifactorial pathophysiology. Evidence for improved and quicker efficacy with safety and longer remission has been noted with combination therapies.