Cause:Hormonal changes of puberty; bacterial (corynebacterium acne)?,, iodides and bromides

Pathophys:Hypertrophic sebaceous glands lead to increased sebum production and desquamation, especially with androgen stimulation, w comedone formation; sebum undergoes lypolysis by bacteria, which, in turn, causes inflammation. Cystic acne is associated with increased androgen levels from partial adrenal 2I-OH deficiency or polycystic ovaries, hence low-dose dexamethasone and/or birth control pills help (Nejm 1983;308:981)

Teenagers; XYY genotype may correlate w severe acne vulgaris and early age of onset (Ann IM 1970;73:270); associated with seborrheic dermatitis

Sx:Acne; iodide and bromide types lack comedones and may be in unusual places

Si:Papules on erythematous base, pustules, comedones, nodules, cysts, scars

HIDRADENITISin axilla or groin, rx with topical and systemic antibiotics, and antibacterial soaps, intralesional steroids; birth control pills occasionally helpful. Avoid I + Ds; rx severe cases with excision of apocrine gland-bearing skin

r/o ACNE ROSACEA(Nejm 2005;352:793), which is central facial; has telangiectases, papules, and pustules without comedones or scarring; rx with dietary vasodilator restriction, topical rx with metronidazole 0.75% cream bid (Med Let 1989;31:75), azelaic acid 15% gel bid, and po tetracycline (Med Let 2007;49:5) w strict photo protection, as below

Rx:

(Nejm 2005;352:1463; Jama 2004;292:726)

Mild:

• Avoid facial creams; wash face bid and hair qod
• Topical rx (Med Let 1996;38:53) with:
• Benzoyl peroxide, resorcinol, salicylic acid (Pernox, Xerac, Fostex, Banoxyl, Syntex, Abiotin)
• Retinoids; all $35/15 gm
• Tretinoin (Retin A, Avita) 0.025, or 0.05, or 0.1% cream or 0.025% or 0.1% gel; adverse effects: burns transiently 1st week, sun sensitivity and thus skin cancer risk, and rarely if hepatic dysfunction can get neuropsych toxicity (Ann IM 1996;124:227);
• Tazarotene (Tazorac) 0.05% or 0.1% crm or gel qd (Med Let 2002;44:52); more effecive and more irritating than the other 2
• Adapalene gel (Differin) q hs, as 0.1% cream, or 0.1% or 0.3% gel
• Antibiotics:
• Erythromycin 2% soln gel or cream bid, or 2, 3, or 5% soln w benzoyl peroxide gel (Benzamycin)
• Clindamycin 1% gel, solution or lotion (Nejm 1980;302:503); w benzoyl peroxide (BenzaClin, Duac)
• Metronidazole 0.75% gel (Metrogel) $38/30 gm, or 1% cream (Noritate) qd-bid; $50/30 gm
• Azelaic acid (Azelex) 20% cream bid; or as 15% gel (Finacea) (Med Let 2003;45:76) bid esp for rosacea; adv effects: stinging, burning; $43/30 gm

Moderate:

• Oral antibiotics:
• Tetracycline (Med Let 2007;49:5) 250-500 mg po bid ($6/mo) until better, then qd and taper, or doxycycline 100 mg po bid ($25/mo) or minocycline 100 mg po bid ($50/mo), of its long-acting once a day form (Solodyn) ($500/mo); because of sunburn, use sunscreen or stop in summer, especially w doxycycline (Nejm 1976;294:43); beware of pregnancy in women since stains infants’ teeth
• Clindamycin po as good or better but higher C. diff colitis risk
• Erythromycin also works
• Azithromycin 250 mg po biw-tiw or less, expensive
• Antiandrogens
• Birth control pills, esp those w 50+ µgm of estradiol (Birth Control) in women, avoid norethindrone- and norgestrel-containing ones since these have some androgen effect
• Spironolactone 50-100 mg po qd
• Flutamide 250-500 mg po qd
• Narrow band blue light (clear light is ineffective) (Med Let 2003;45:50)
• Handheld heat devices (Med Let 2007;49:51)

Severe/cystic:

• Retinoids:
• Isotretinoin (Accutane) (Med Let 2002;44:82) 1-4 mg/kg po qd × 5 mo after derm consult; $100+/mo; 95% remissions; adverse effects (FDA Bull 13:21): 33% teratogen in 1st trimester (Nejm 1985;313:837), difficult to obtain for potentially pregnant women (Nejm 1989;320:1007); elevated uric acid; regional ileitis; corneal opacities; elevated lipids may cause atherosclerosis (Nejm 1985;313:981); pseudotumor cerebri; hyperostosis, at least at higher doses, which are used in ichthyosis (Nejm 1983;308:1012); arthritis and fatigue limit use in athletes (R. Kenney 12/85); possibly depression and suicide
• Acitretin (Soriatane) (Rx Let 1997;4:64) po qd; less long-acting metabolites than isotretinoin but alcohol counteracts this advantage by converting it to those toxic forms
• Low-dose dexamethasone, with or without birth control pills (Nejm 1983;308:981)
• Intralesional steroids
• Cryotherapy