PATHOGENS

• Propionibacterium species
• Acne vulgaris is a condition where multiple factors contribute to its pathogenesis, including abnormal follicular keratinization and occlusion, excessive oil production and bacterial superinfection.

CLINICAL

• Hx: insidious development of multiple follicular lesions with periods of clinical improvement and exacerbation. Peak prevalence: age 17, but may start as early as 8 yrs.
• Most cases involute spontaneously and completely after a few years, but a small percentage remains active through adult life. Some patients first develop acne in their 3rd and 4th decades of life.
• PE: any combination of open and closed comedones, inflammatory papules, pustules, nodules and cysts, affecting the face, neck, upper chest, back and/or proximal extremities.
• Other associated findings: excessive oiliness of the skin, post-inflammatory hyper/hypo-pigmentation, atrophic or hypertrophic scars, excoriations, hirsutism and/or alopecia in women.
• Lab: no dx test for acne vulgaris
• DDx: folliculitis, miliaria, acneiform drug eruptions, rosacea, perioral dermatitis, follicular mucinosis, papular urticaria, follicular eczema.

TREATMENT

• Determine the predominant type of skin lesion to best choose the most appropriate type of treatment.
• If both open and closed comedones present, with few or no inflammatory papules, the best therapy is topical retinoic acids, i.e., tretinoin, adapalene or tazarotene.
• If comedones are few, and inflammatory papules and pustules moderate, best results obtained with a combination of topical retinoic acids and topical antibiotics, azelaic acid or benzoyl peroxide. Very mild cases can be controlled with either one of these medications alone.
• In moderate to severe cases with numerous inflammatory papules and pustules, use systemic antibiotics and either benzoyl peroxide, azelaic acid or retinoic acids.
• In nodulo-cystic acne or acne conglobata that has not responded to systemic antibiotics alone or in combination with topical medications, isotretinoin (Accutane) is the drug of choice. For female patients who are sexually active with males, two methods of birth control are required while on this medication and for 3 months after the treatment. Monthly serum pregnancy tests are also mandatory. For both males and females, monitoring of liver function tests, serum cholesterol and triglyceride levels are also required regularly.
• Follow patient for at least 4-6 wks before deciding whether any given therapy is working or not.

Topical Therapy

• Benzoyl peroxide 2.5-10% (Acne-Aid, Ambi 10, Benoxyl 10, Benzac, Brevoxyl, Desquam, PanOxyl) lotion, liquid soap, cream or gel qday-bid.
• Erythromycin 2% (Akne-Mycin, A/T/S, Emgel, Erycette, EryDerm, Erythra-Derm, Erygel, Erymax, Staticin, Theramycin Z, T-Stat) lotion, solution, cream or gel qhs
• Benzoyl peroxide 5%/ erythromycin 3% gel (Benzamycin) qHS; Benzoyl peroxide 5%/ clindamycin 1% gel (Benzaclin, Duac) qHS.
• Clindamycin solution, lotion or gel (Cleocin T, Clindagel, Clindets) qhs.
• Sodium sulfacetamide 10% lotion (Avar, Clenia, Plexion, Rosula, Rosanil, Sulfacet-R, Klaron) qday-bid.
• Azelaic acid 20% (Azelex, Finacea, Finevin) cream qday-bid.
• Tretinoin 0.025-0.1% (Retin-A, Retin-A micro, Renova, Avita, Altinac) cream, gel, solution qhs.
• Adapalene 0.1% (Differin) gel qhs.
• Tazarotene 0.05%. 0.1% (Avage, Tazorac) cream or gel qhs.
• Salicylic acid 3-5% or lactic acid 12% compounded in lotion or cream base qday-bid.

Systemic Therapy

• Tetracycline 250-500mg PO qday-bid and reassess in 1-2 mos.
• Doxycycline 50-100mg PO qday-bid and reassess in 1-2 mos.
• Minocycline 50-100mg PO qday-bid and reassess in 1-2 mos.
• Erythromycin 250-500mg PO qid or 333mg PO tid x 1 mo.
• TMP/SMX DS 1 tab PO qday-bid and reassess in 1 mo.
• Azithromycin (Z-Pack) q 15d or q mo.
• Dapsone 50-100mg PO qday.
• Isotretinoin (Accutane) 0.5-1mg/kg/day x 20 wks.
• Hormonal therapy: oral contraceptives, estrogen or anti-androgen agents (spironolactone, flutamide).
• Prednisone 20-40 mg PO qd x 1-2 wks (in cases of acne fulminans, pyoderma faciale or in early association with isotretinoin).